HYDRAULIC  ELEVATORS 


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Ne^vv^Yor-k. 


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HYDRAULIC 

ELEVATORS 


THEIR  DESIGN,  CONSTRUCTION,  OPERATION 
CARE  AND  MANAGEMENT 


BY 

WILLIAM  BAXTER,  JR. 

Author  of  "Practical  Talks  on  Electricity,3 
"Switchboards,"  Etc. 


1910 
McGRAW-HILL   BOOK   COMPANY 

239  WEST  39th  STREET,  NEW  YORK 

6  BOUVERIE  STREET,  LONDON,  E.  C. 


Copyright  1910  by  the  McGraw-Hill  Book  Company 


o       -  ,^,  , .-.,   , 


v 


CONTENTS 


CHAPTER  PAGE 

I.     Fundamental  Principles  of  Different  Types 1 

II.     Counterbalancing — The  High-Pressure  System 11 

III.  Plunger  Hydraulic  Elevators — Plunger  Elevators 18 

IV.  Horizontal  Cylinder  Types— "  Pushing"  and  "  Pulling"  Types .  .        21 
V.     Counterbalancing  the  Lifting  Ropes  of  Elevator  Cars 25 

VI.     General  Arrangement  of  Hydraulic  Elevator  Systems 30 

VII.     Vertical   Hydraulic   Elevators — Simple   Low-Pressure   Vertical 

Type  Otis  Elevator  with  Hand-Rope  Control 33 

VIII.     Low-Pressure  Vertical  Elevators,  Lever  Control 45 

IX.     Pilot -Valve    Control — Regulating    Valves — Speed    Regulating 

Valves 52 

X.     Safety  Devices '. 60 

XL     Good  Features  of  Magnetic  Valve  Control;   Obstacles  that  Pre-    - 

vent  its  General  Use — Descriptions  of  Control  Systems .  .  .  ^  .  .        66 
XII.     Magnetic  Controller  for  Battery  Current 70 

XIII.  Double-Power  Hydraulic  Elevator  System 79 

XIV.  Otis,  Running-Rope  System * 85 

XV.     Principal  Causes  of  Disordered  Mechanism  and  How  Prevented 

or  Removed — Directions  for  Packing  Pistons  or  Valves 89 

XVI.     Automatic  Devices  Used  for  Stopping  Cars  at  Top  and  Bottom 

Landings;  Their  Care  and  Their  Value  as  Safety  Appliances .  .      100 

XVII.     Effect  of  Stretching  of  the  Ropei 106 

XVIII.     Construction   of   Traveling-Sheave    Frames,    Foundations   and 

Supports,  to  Avoid  Piston  and  Cylinder  Friction 112 

XIX.     Why  the  Piston  is  Weighted 120 

XX.     The  Electrical   Features  of  Vertical  Cylinder  Elevators,  'with 
Magnet  Control;    Operation  and  Care  of  Pilot  Valves  and 

Connecting  Mechanisms 123 

XXI.     Horizontal  Hydraulic  Elevators , 131 

XXII.     Description   of   the    "Pulling"    Type   of   Horizontal    Elevator, 

Showing  the  Operating  Principle  of  the  Whittier  Machine ....      142 

XXIII.  The    Marse-Williams ;     Construction    and    Operation    of    the 

Valves 147 

XXIV.  Crane  Horizontal  "Pushing"  Machine:    How  the  Stop-Motion 

Gets  Out  of  Adjustment;  the  Cylinders  and  Other  Parts.  ...      155 
XXV.     Crane    Horizontal    Machine;     Description   of   Automatic    Stop 

Valve ;   Packing  the  Main  Piston  and  Cylinders 159 

XXVI.     Construction    Details   of   the    Whittier   Machine   with   Special 

Reference  to  the  Stop- Valve  Mechanism 165 

XXVIII.  Overhead  Sheaves  and  Bearings;  Kind  of  Lubricant  Best  Suited 
for  Them ;  Discharge  Pipe  Relief  Valves ;  the  Use  of  Strain- 
ers ;  When  Required 171 

XXVIII.     Discussion  Relative  to  the  Details  of  the  Morse  and  Williams 

"  Pulling"  Machines 176 

330524 


CONTENTS 

CHAPTER  PAGE 

XXIX.     High-Pressure  Hydraulic  Elevators 187 

XXX.     Operation  of  the  Main  and  Pilot  Valves. of  the  Otis  Vertical 

Elevator — the  Electrical  Control  Sometimes  Employed 198 

XXXI.  Construction  and  Operation  of  the  Accumulators  and  the  Auto- 
matic Valves  Used  With  Them 205 

XXXII.     Automatic  Stop-Valves  With  Otis  High-Pressure  Machines 212 

XXXIII.  Adjustment  and  Care  of  Automatic  Stop- Valves  and  Mechanism 

of    High-Pressure    Elevators;     How   to    Pack   the    Different 
Parts;   Kinds  of  Packing  Used 221 

XXXIV.  Stop-Valves  Used  With  Accumulators;    General  Arrangement 

of   Apparatus  in   High-Pressure   Systems;    the   Pumps   and 

Their  Operation 228 

XXXV.     Plunger  Elevators 236 

XXXVI.     Operation  of  Main  and  Pilot  Control  Valves;    Comparison  of 

Different  Control  and  Automatic  Stop- Valves 254 

XXXVII.     Rack-and-Pinion  Valves  for  Otis  Freight  Elevators;    Type  of 
Valve  Used  for  High  Speed ;   Notes  on  the  Care  of  the  Plunger 

and  Ropes 263 

XXXVIII.     Replacing   Worn   Shoes;     How   to    Disconnect  the   Plunger; 

Care   Observed  in   Handling    Parts 272 

XXXIX.     The  "Standard"  Plunger  Elevator;    Principal  Differences  Be- 
tween This  and  the  Otis  Types;    Valve,   Construction  and 

Operation 279 

XL.     Operation  of  the  Pilot  and  Main  Valves;   How  the  Adjustments 

are  Made 286 

XLI.     Construction  and  Operation;    Details  of  the  Highest  Type  of 
Passenger  Elevator  Made  by  the  Standard  Plunger  Elevator 

Company 300 

XLIL     Practical  Instructions   in    the  Care  and   Management   of  the 
"Standard"  Plunger  Elevator;  Essential  Features  to  Look 

Out  For 307 

XLIII.  Hand  Rope  Control  for  Freight  Elevators;  Pump  and  Con- 
nections Used  with  "Safe  Lifters";  Locking  Device  for 
Plunger  Elevators;  Hand-Rope  Control 313 


CHAPTER  I 
FUNDAMENTAL   PRINCIPLES    OF   DIFFERENT    TYPES 

The  principal  mechanism  of  a  hydraulic  elevator  is  very  simple, 
although  it  does  not  appear  to  be  so  from  casual  inspection  of  a  first-class 
installation  in  a  large  office  building.  This  is  due  mainly  to  the  fact  that 
the  apparatus  is  all  of  large  dimensions  and  so  disposed  that  only  a 
portion  of  it  can  be  seen  from  any  one  point.  It  is  also  due  to  the  fact 
that  a  number  of  small  parts  are  added,  the  function  of  which  is  to 
contribute  to  the  perfection  and  safety  of  operation. 

The  principle  of  operation  of  the  hydraulic  form  of  elevator  is  as 
simple  as  the  construction  of  the  mechanism,  and  consists  in  utilizing  the 
force  developed  by  the  pressure  of  water  in  a  hydraulic  cylinder  to  lift 
a  weight,  which  generally  is  the  elevator  car,  but  in  some  cases  is*  not. 
The  water  under  pressure  that  supplies  the  elevator  cylinder  may  be 
derived  from  street  mains,  from  an  open  tank  placed  on  an  elevation 
(for  example,  the  roof  of  the  building),  or  from  a  pressure  tank  placed 
in  any  convenient  location. 

The  simplest  form  of  hydraulic  elevator  is  illustrated  diagram- 
matically  in  Fig.  i.  The  car  is  suspended  from  one  or  more  ropes  that 
pass  over  a  sheave  A,  located  at  the  top  of  the  elevator  well,  and  run 
down  to  the  upper  end  of  a  piston  rod  R.  This  rod  carries  at  its  lower 
end  a  piston  P  that  fits  watertight  in  the  lifting  cylinder  C.  Water 
under  pressure  is  admitted  to  the  cylinder  above  the  piston,  through 
the  pipe  /,  and  the  piston  is  thereby  forced  downward,  hoisting  the  car. 
To  make  the  apparatus  complete,  elementally,  all  that  is  required  is  a 
valve  in  the  pipe  7  which,  when  turned  in  one  direction,  will  connect  the 
cylinder  with  the  pressure  tank,  or  other  source  of  supply,  and  when 
turned  in  the  other  direction  will  stop  off  the  supply  from  the  pressure 
tank  and  connect  the  upper  end  of  the  cylinder  with  a  discharge  tank. 
When  moved  to  the  central  position,  it  must  close  the  outlet  from  the 
cylinder  so  that  the  water  contained  therein  cannot  escape. 

It  is  evident  that  when  the  water  is  permitted  to  flow  out  of  the 
upper  end  of  the  cylinder,  if  the  elevator  car  weighs  more  than  the 
piston  P,  the  piston  will  run  up  and  the  car  will  run  down.  If,  when 
the  piston  is  in  any  position  in  the  cylinder,  from  the  uppermost  to  the 


2  HYDRAULIC  ELEVATORS 

lowest,  the  flow  of  water  out  of  the  cylinder  is  stopped,  the  motion  of 
the  piston  will  be  arrested  and  the  car  will  be  stopped. 

The  load  that  can  be  lifted  when  the  piston  P  is  forced  down  will 
depend  upon  the  pressure  of  the  water;  the  higher  the  pressure  the 
greater  the  permissible  load.  If  it  is  desired  that  the  elevator  be  able  to 
lift  loads  varying  anywhere  between  100  and  2000  pounds,  then  the 
pressure  of  the  water  admitted  to  the  cylinder  must  be  sufficient  to  lift 
the  maximum  load.  Whether  the  load  lifted  is  the  maximum  or  the 
minimum,  the  same  amount  of  water  will  be  required  to  lift  the  car 


J 


Car 


Car 


FIG. 


FIG.  2 


from  the  lower  position  to  the  upper  position  D,  hence  the  same  amount 
of  power  will  be  required  if  the  pressure  of  the  water  remains  the  same. 
In  practice  elevators  are  supplied  with  water  at  constant  pressure,  in 
nearly  every  type  used;  and  in  these,  as  shown  in  the  foregoing,  the 
energy  absorbed  to  make  a  trip  with  the  empty  car  is  equal  to  that 
required  to  lift  the  maximum  load.  This  is  an  inherent  defect  in 
hydraulic  elevators  that  many  inventors  have  tried  to  overcome,  but  no 
one  has  succeeded  in  doing  so  in  a  satisfactory  manner  up  to  the  present 
time.  There  is  a  system  in  use  which  partially  accomplishes  the  result, 


FUNDAMENTAL  PRINCIPLES  OF  DIFFERENT  TYPES  3 

and  others  have  been  devised  that  wholly  accomplish  it,  but  these  latter 
possess  defects  in  other  directions  that  render  them  undesirable. 

The  elevator  represented  in  Fig.  i  is  what  is  called  a  "one-to-one" 
geared  machine,  being  so  called  from  the  fact  that  the  car  moves  through 
the  same  distance  that  the  piston  does.  This  class  is  only  susceptible 
of  application  in  a  few  cases.  It  is  not  suited  to  the  operation  of 
elevators  that  run  to  the  top  of  the  building,  as  can  be  clearly  seen  from 
the  diagram,  the  uppermost  position,  D,  of  the  car  being  less  than  one- 
half  the  distance  up  to  the  overhead  sheave  A. 

THE  WATER-BALANCE  ELEVATOR. 

A  simple  way  of  arranging  a  one-to-one  gear  machine  so  that  the 
elevator  may  run  to  the  top  of  the  building  is  illustrated  in  Fig.  2.  This 
is  what  is  known  as  a  "water-balance"  elevator,  and  is  a  type  that  was 
used  quite  extensively  in  some  of  the  large  western  cities  some  years 
ago,  and  so  far  as  I  know  may  still  be  in  use,  but  is  no  longer  manu- 
factured. In  this  elevator  the  car  is  suspended  from  wire  ropes  that 
pass  over  the  overhead  sheave  A  and  carry  at  their  other  ends  an  iron 
bucket  B.  This  bucket  weighs  less  than  the  empty  car,  but  is  of  such 
size  that  when  filled  with  water  it  will  overbalance  the  car  and  its 
maximum  load.'  If  the  car  is  at  the  bottom  of  the  building  and  the 
bucket  at  the  top,  as  in  the  illustration,  and  the  operator  desires  to  run 
the  car  up,  he  pulls  on  a  hand  rope  that  opens  a  valve  in  the  pipe  7  and 
allows  water  to  flow  into  the  bucket.  When  a  sufficient  amount  of  water 
has  run  into  the  bucket  to  overbalance  the  car  and  its  load,  the  latter 
will  begin  to  move  upward,  and  then  the  supply  of  water  is  cut  off. 
The  velocity  of  the  elevator  car  is  controlled  by  a  brake  that  grips  the 
guides  that  the  car  runs  on  and  is  controlled  by  the  operator  in  the  car; 
by  means  of  the  same  brake  the  car  is  stopped.  When  the  elevator  is 
at  the  top  of  the  building  and  the  bucket  at  the  bottom,  the  operator  to 
make  the  down  trip  pulls  a  rope  that  opens  a  valve  in  the  bottom  of 
the  bucket  and  lets  out  water  until  the  bucket  becomes  lighter  than 
the  car. 

With  this  arrangement  it  is  evident  that  the  amount  of  water  used 
for  each  trip  of  the  car  is  not  the  same,  but  depends  upon  the  load ;  the 
same  is  true  for  the  down  trip,  hence  the  energy  used  is  nearly  propor- 
tional to  the  weight  lifted  and  lowered.  This  statement  is  intended  to 
apply  to  the  total  work  done;  that  is,  to  an  all-day  run.  It  is  not  true, 
however,  with  reference  to  a  single  trip,  either  up  or  down.  On  any 
up  trip  the  amount  of  water  that  must  be  let  into  the  bucket  depends 
not  only  upon  the  load,  but  also  upon  the  amount  of  water  remaining  in 
the  bucket  from  the  previous  trip.  On  the  down  trip  the  amount  of 


4  HYDRAULIC  ELEVATORS 

water  that  must  be  let  out  of  the  bucket  depends  on  the  amount  it  con- 
tains as  well  as  upon  the  load,  and  is  small  if  the  load  is  great,  and 
large  if  the  load  is  light,  so  that  it  is  inversely  proportional  to  the  load 
instead  of  directly  proportional.  For  an  all-day  run,  however,  the 
statement  as  made  is  substantially  correct. 

The  velocity  at  which  the  elevator  car  can  be  run  is  very  high,  and 
if  the  operator  is  sufficiently  expert  the  smoothness  of  motion  is  all  that 
can  be  desired,  and  stops  can  be  made  without  any  perceptible  jar;  but 
if  the  brake  fails  to  work,  the  car  can  shoot  up  to  the  top  of  the  building 
or  down  the  bottom  with  a  velocity  great  enough  to  cause  disaster. 

One  of  these  water-balance  elevators  was  installed  in  the  Western 
Union  building  at  the  corner  of  Broadway  and  Dey  street,  New  York, 
about  twenty-five  years  ago,  but  was  removed  some  years  thereafter. 
So  far  as  I  know  it  ran  without  any  mishaps,  but  the  element  of  danger 
involved  is  great,  and  on  that  account  it  never  was  looked  upon  with 
favor  by  eastern  elevator  experts. 

TWO-TO-ONE   ELEVATOR. 

In  order  that  an  elevator  may  be  run  to  the  top  of  the  building  by 
what  we  may  call  the  regular  type  of  hydraulic  elevator,  it  is  necessary 
that  the  gear  be  greater  than  one-to-one;  that  is,  the  car  must  travel  a 
greater  distance  than  the  piston  in  the  lifting  cylinder.  Fig.  3  is  a 
diagrammatic  representation  of  an  elevator  geared  two-to-one.  In  this 
arrangement  the  lifting  ropes  running  up  from  the  car  pass  over  the 
overhead  sheave  A  and  then  under  a  sheave  B  that  is  supported  in  a 
frame  attached  to  the  upper  end  of  the  piston  rod.  The  ends  of  the 
lifting  ropes  are  anchored  to  a  strong  support  G.  If  the  piston  moves 
down  through  a  distance  of  ten  feet,  the  car  will  be  drawn  up  through 
a  distance  of  twenty  feet,  and  when  the  car  reaches  the  position  D,  the 
piston  will  be  at  the  bottom  of  the  cylinder. 

This  elevator  can  be  made  to  operate  in  either  of  two  ways,  one  by 
admitting  water  on  top  of  the  piston  and  the  other  by  admitting  water 
below  the  piston.  If  it  is  to  be  operated  by  admitting  water  on  top  of 
the  piston,  the  latter  must  weigh  somewhat  less  than  twice  the  weight 
of  the  empty  car,  so  that  the  latter  may  be  able,  without  any  load,  to 
descend  and  draw  up  the  piston.  If  the  elevator  is  to  be  operated  by 
admitting  water  under  the  piston,  then  the  latter  must  weigh  something 
more  than  twice  as  much  as  the  car  when  fully  loaded,  so  that  it  may 
be  able  to  lift  the  maximum  load.  The  deficiency  in  the  first  case  and 
the  excess  of  weight  in  the  second  must  be  enough  to  overcome  all  the 
friction  of  the  apparatus  and  impart  to  the  elevator  the  required  velocity. 
The  amount  of  this  unbalanced  weight,  as  it  is  called,  will  vary  from 


FUNDAMENTAL  PRINCIPLES  OF  DIFFERENT  TYPES  5 

300  to  500  pounds,  according  to  the  size  and  speed  of  the  car,  and  as  the 
gear  is  two-to-one,  the  piston  will  be  underbalanced  in  one  case  and  over- 
balanced in  the  other,  from  600  to  1000  pounds. 

THREE-TO-ONE   TYPE. 

Elevators  geared  two-to-one  are  used  only  in  low  buildings,  say  sixty 
feet  high  or  less.  For  higher  runs  the  gear  is  made  anywhere  from 
three-to-one  up  to  eight-to-one.  A  three-to-one  elevator  is  shown  in 


FIG.  3 


FIG.  4 


Fig.  4;  here  the  lifting  ropes,  instead  of  being  anchored  after  passing 
under  the  sheave  attached  to  the  upper  end  of  the  piston  rod,  pass  over 
a  stationary  sheave  F,  which  is  firmly  secured  to  a  support  G,  and  then 
run  down  and  are  secured  to  the  frame  that  carries  the  sheave  B.  In 
this  case,  the  'piston  P  travels  only  one-third  the  distance  traveled  by 
the  car,  the  latter  running  up  to  the  position  D,  while  the  piston  runs 
down  to  the  lower  end  of  the  cylinder  C. 

This  type  of  elevator,  like  Fig.  3,  can  be  arranged  so  that  water  can 
be  admitted  under  the  piston  to  push  it  up,  but  as  it  requires  three 


6  HYDRAULIC  ELEVATORS 

pounds  in  the  piston  to  balance  one  pound  in  the  car,  the  weight  would 
be  very  great,  and  so  far  as  I  know  this  arrangement  has  never  been 
used.  In  fact,  even  in  machines  geared  two-to-one  it  has  been  used  in 
only  one  design,  which  was  brought  out  about  ten  years  ago  and  installed 
in  the  American  Tract  Society  building  in  New  York  City  and  in  several 
buildings  in  western  cities.  Its  construction  differed  from  Fig.  3  in  that 
a  plunger  was  used  in  place  of  a  piston  and  rod,  this  change  being  made 
to  simplify  the  apparatus  and  also  to  provide  an  easy  way  of  obtaining 
the  weight  necessary  to  pull  up  the  fully  loaded  car.  The  design  was 
known  as  the  upright-plunger  elevator.  It  is  not  manufactured  at  the 
present  time. 

DETERMINING   THE  GEAR. 

For  reasons  that  will  be  explained  hereafter,  vertical  elevator  cylinders 
are  seldom  made  with  a  stroke  greater  than  30  or  32  feet ;  therefore,  if 
the  hight  of  a  building  is  such  that  a  three-to-one  gear  would  require  a 
cylinder  of  more  than  32  feet  stroke,  the  gear  is  increased  to  four,  six  or 
eight-to-one.  The  gear  is  in  every  case  equal  to  the  rise  of  the  car 
divided  by  the  stroke  of  the  piston,  hence  a  four-to-one  gear  can  be  used 
for  a  car  travel  of  not  more  than  125  feet,  a  six-to-one  for  180  and 
eight-to-one  for  240  feet. 

It  sometimes  becomes  desirable  to  determine  the  gear  of  an  elevator 
already  installed  in  a  building,  and  this  cannot  be  done  readily  by 
dividing  the  run  of  the  car  by  the  stroke  of  the  piston  unless  these 
figures  are  known,  because  it  is  difficult  to  make  the  measurements.  It 
is  not  necessary  to  go  to  this  trouble,  however,  as  the  gear  can  be 
determined  from  an  inspection  of  the  lifting  ropes  running  up  from  the 
sheave  frame  attached  to  the  top  of  the  piston  rod.  Referring  to  Fig.  I 
it  will  be  seen  that  only  one  rope  runs  up  from  the  piston  rod,  and  this 
is  a  one-to-one  gear.  In  Fig.  3  one  rope  runs  up  from  the  left  side  and 
one  from  the  right  side  of  the  sheave  B,  and  this  is  a  two-to-one  gear. 
In  Fig.  4  there  are  three  ropes  running  up  from  the  piston-rod  sheave, 
and  this  is  a  three-to-one  gear.  In  Fig.  5  there  are  four  ropes  running 
up  from  the  sheaves  B  and  H,  and  this  is  a  four-to-one  gear.  In  all 
higher  gears  this  same  relation  holds  good,  so  that  to  find  the  gear  of  any 
elevator  all  that  is  necessary  is  to  count  the  number  of  ropes,  or  sets  of 
ropes,  that  run  up  from  the  sheaves  attached  to  the  piston  rod. 

In  Fig.  5  it  will  be  noticed  that  the  sheave  H  is  placed  above  the 
sheave  B.  This  arrangement  is  used  in  vertical  rigging  so  as  to  reduce 
the  dimensions  of  the  well  in  which  the  sheaves  travel.  If  the  gear  is 
greater  than  four-to-one,  so  as  to  require  two  or  more  stationary  sheaves, 
these  are  also  usually  arranged  one  above  the  other.  With  this  con- 


FUNDAMENTAL  PRINCIPLES  OF  DIFFERENT  TYPES  7 

struction  it  is  necessary  that  the  lower  of  the  traveling  sheaves  be  of 
larger  diameter  than  the  one  above  it,  and  that  the  upper  stationary 
sheave  be  the  larger.  This  is  necessary  in  order  to  prevent  the  ropes 
from  rubbing  against  each  other,  as  can  be  easily  understood  from 
inspection  of  Fig.  5. 

In  Fig.  4  it  will  be  noticed  that  the  centers  of  the  sheaves  B  and  F 
are  not  in  line  vertically,  F  being  offset  to  the  right.  This  arrangement 
is  required  so  as  not  to  have  the  ropes  pull  the  piston  rod  to  one  side. 


FIG.  5 


FIG.  6 


In  Fig.  5  all  the  sheave  centers  are  on  the  same  vertical  line,  which 
arrangement  is  practical  because  all  the  ropes  run  vertically.  With  any 
odd  gear,  the  lowest  of  the  stationary  sheaves  would  have  to  be  offset, 
as  in  Fig.  4,  and  on  that  account  its  diameter  would  be  much  less  than 
that  of  the  other  sheaves.  For  this  reason  the  only  odd  gear  used  is 
three-to-one,  gears  above  four-to-one  being  even,  such  as  six-to-one  and 
eight-to-one.  In  actual  elevators  the  frame  that  holds  the  traveling 
sheaves  is  provided  with  shoes  to  run  on  guides,  so  that  with  an  odd 
gear,  if  all  the  sheaves  were  placed  in  line,  the  side  thrust  would  not 


8  HYDRAULIC  ELEVATORS 

produce  any  serious  results  other  than  to  increase  the  friction  and  wear 
at  the  upper  end  of  the  guides. 

SIMPLE  BALANCED  VALVE. 

In  the  "regular"  types  so  far  discussed,  water  under  pressure  is 
admitted  to  the  cylinder  to  move  the  piston,  and  it  remains  to  show  how 
the  flow  of  water  is  controlled  so  as  to  cause  the  piston  to  move  upward 
or  downward  or  to  stop  at  any  desired  point.  All  this  is  accomplished 
by  a  single  valve  of  very  simple  construction,  which  can  be  readily 
understood  by  reference  to  Fig.  6.  In  this  diagram  the  valve  is  shown 
as  consisting  of  double  pistons,  V  V,  mounted  on  a  valve-rod  that  projects 
upward  from  the  valve  chamber.  The  actual  form  of  the  valve  differs 
considerably  in  the  elevators  of  different  manufacturers,  but  the  principle 
of  operation  of  all  is  substantially  the  same. 

Means  are  provided  whereby  the  operator  in  the  car  can  move  the 
valve  in  either  direction  or  bring  it  to  the  central  position,  so  as  to  cause 
the  elevator  to  ascend,  descend  or  stop.  If  the  valve  be  depressed  to 
the  position  in  which  it  is  shown  in  Fig.  6,  water  from  the  pressure  tank 
will  flow  in  through  the  pipe  /  to  the  valve  chamber  and  passing  out 
through  the  port  /  will  enter  the  cylinder  and  force  the  piston  down.  If 
the  valve  be  depressed  so  as  to  open  the  ports  wide,  as  shown,  the 
maximum  amount  of  water  will  flow  into  the  cylinder,  and  the  piston 
will  be  driven  down  with  the  maximum  velocity.  If  the  valve  is  depressed 
only  enough  to  uncover  a  small  portion  of  the  ports,  only  a  small  volume 
of  water  will  pass  through,  and  as  a  result  the  piston  will  travel  down 
at  a  slower  speed.  Thus  the  velocity  of  the  piston,  and,  therefore,  that 
of  the  car,  can  be  controlled  by  varying  the  position  of  the  valve. 

If,  when  the  piston  is  moving  down,  the  valve  be  raised  so  that  V 
covers  the  port  /,  the  flow  of  water  into  or  out  of  the  cylinder  will  be 
prevented  and  the  piston  will  be  held  stationary  in  the  cylinder.  As 
the  water  cannot  be  compressed,  it  makes  no  difference  where  the 
piston  may  be,  whether  near  the  top  or  bottom;  its  motion  will  be 
arrested  whenever  the  port  /  is  covered.  As  it  is  possible  for  the 
operator  to  move  the  valve  almost  instantaneously  over  the  port  /, 
unless  means  are  provided  to  prevent  such  sudden  movement,  the  elevator 
is  liable  to  be  stopped  too  abruptly.  To  avoid  sudden  stops  various 
devices  are  used,  all  of  which  will  be  fully  described  hereafter. 

If,  when  the  piston  has  been  forced  down  to  the  bottom  -of  the 
cylinder,  the  valve  is  raised  so  that  V  passes  above  the  port  /,  as  shown 
at  6a,  then  the  flow  of  water  from  the  pressure  tank  will  be  prevented, 
and  the  water  in  the  cylinder  will  pass  out  through  the  port  /  to  the 
discharge  pipe  O,  as  indicated  by  the  arrows,  and  the  piston  P  will  move 


FUNDAMENTAL  PRINCIPLES  OF  DIFFERENT  TYPES  9 

up  as  fast  as  the  water  escapes.  To  vary  the  velocity  of  the  piston  on 
its  upward  motion,  all  that  is  necessary  is  to  vary  the  position  of  the 
valve  so  that  the  part  V  may  uncover  as  much  of  the  port  /  as  may  be 
required  to  develop  the  desired  car  speed.  The  function  of  the  upper 
piston  V  is  merely  to  balance  the  water  pressure  on  the  valve. 

The  arrangement  of  cylinder  and  valve  illustrated  in  Fig.  6  was  used 
exclusively  in  the  early  days  of  hydraulic  elevators,  but  is  not  used  at 
the  present  time  except  in  high-pressure  machines. 

It  is  obvious  that  when  the  piston  P  is  at  the  top  of  the  cylinder  the 
pressure  acting  on  it  is  not  as  great  as  when  it  is  at  the  bottom,  for  in 
the  latter  position  the  weight  of  the  water  above  the  piston  is  added  to 
the  pressure.  This  would  not  make  a  material  difference  with  a  short 
cylinder,  neither  would  it  count  for  much  if  the  pressure  of  the  water 
used  to  operate  the  elevator  were  600  or  700  pounds.  Suppose,  however, 
that  the  water  were  under  a  pressure  of  only  50  pounds  per  square  inch 
and  that  the  stroke  of  the  piston  were  30  feet ;  then  the  weight  of  water 
above  the  piston  when  the  latter  is  in  the  lowest  position  will  amount  to 
practically  13  pounds  per  square  inch  of  piston  surface,  so  that  the 
actual  pressure  per  square  inch  acting  to  force  the  piston  down  will  be 
63  pounds,  while  with  the  piston  at  the  top  of  the  cylinder  it  will  be 
only  50  pounds. 

EQUAL    PRESSURE    ARRANGEMENT. 

Early  in  the  history  of  hydraulic  elevators  the  inequality  in  pressures 
was  overcome  by  the  simple  construction  illustrated  in  Fig.  7.  The  pipe  / 
connecting  with  the  pressure  tank  delivers  water  to  the  ''circulating 
pipe"  K,  which  connects  the  upper  end  of  the  cylinder  with  the  valve 
chamber  in  the  manner  clearly  shown.  If  the  piston  P  be  at  the  bottom 
of  the  cylinder  and  the  valve  be  depressed  to  the  position  shown  in  the 
sketch,  the  water  above  the  piston  will  descend  through  the  circulating 
pipe  K  to  the  valve  chamber  and  through  the  port  /  to  the  lower  end  of 
the  cylinder,  so  that  as  the  piston  moves  upward  the  water  is  trans- 
ferred from  the  upper  end  to  the  lower  end  of  the  cylinder.  (The  piston 
is  drawn  upward  by  the  weight  of  the  car  and  load.)  With  the  valve  in 
this  position  both  ends  of  the  cylinder  are  in  direct  communication  with 
the  pressure  tank;  consequently  all  the  space  in  the  cylinder,  the  circu- 
lating pipe  and  the  valve  chamber  will  be  filled  with  water.  Now 
suppose  that  the  piston  is  at  the  top  of  the  cylinder,  and  that  the  valve 
is  raised  until  the  lower  part  V  is  above  the  port  /;  then  the  water  under 
the  cylinder  will  flow  outj  and  water  from  the  pressure  tank  will  fill  the 
upper  end  of  the  cylinder.  The  pressure  now  acting  on  the  piston  will 
be  the  pressure  of  the  water  on  top  plus  the  suction  of  the  water  under 
the  piston;  the  latter  will  decrease  as  fast  as  the  piston  runs  down,  and 


10 


HYDRAULIC  ELEVATORS 


the  weight  of  water  above  the  piston  will  increase  at  the  same  rate,  so 
that  the  net  downward  effort  on  the  piston  remains  constant  throughout 
the  stroke. 

The  circulating  pipe  cannot  be  used  with  cylinders  longer  than  about 
32  feet,  for  the  same  reason  that  pumps  cannot  lift  water  to  any  greater 
hight  than  this;  that  is,  that  the  pressure  of  the  atmosphere  will  not 
hold  water  up  against  the  under  side  of  the  piston  to  any  greater  hight. 
It  is  for  this  reason  that  cylinders  are  seldom  made  for  piston  strokes 
greater  than  about  30  feet.  In  some  cases,  for  one  reason  or  another, 


i  p  "i 

1 

=  i 

:>- 

--£ 

ffi 

JL 

,( 

t 

==i 

1 

^Z       c 

FIG.  7 


FIG.  8 


it  becomes  necessary  to  use  a  cylinder  of  greater  length,  but  when  this 
is  done  the  discharge  pipe  is  provided  with  a  goose  neck,  as  shown  in 
Fig.  8,  the  top  bend  of  which  rises  above  the  line  A-A,  the  distance 
from  this  line  to  the  under  side  of  the  piston  when  it  is  at  the  top  of 
the  cylinder  being  about  30  feet. 

At  the  present  time  many  elevators  are  operated  with  water  under  a 
pressure  of  about  750  pounds  per  square  inch,  and  with  these  the  circu- 
lating pipe  is  not  used,  as  the  inequality  in  pressure  due  to  the  weight 
of  the  water  is  not  sufficient  to  make  it  necessary.  The  difference 
between  50  and  63  pounds  is  a  great  deal,  relatively,  but  the  difference 
between  750  and  763  is  less  than  2  per  cent. 


CHAPTER  II 
COUNTERBALANCING— THE  HIGH-PRESSURE  SYSTEM 

Looking  at  Fig.  9,  it  can  easily  be  seen  that  the  hydraulic  cylinder 
acts  only  to  lift  the  car  and  that  the  latter  is  lowered  by  its  own  weight 
combined  with  that  of  the  load.  This  being  the  case,  it  is  evident  that 
the  empty  car  must  be  heavy  enough  to  pull  up  the  piston,  the  piston- 
rods,  the  traveling  sheave  and  frame  and,  in  addition,  to  overcome  all 
the  friction  of  the  moving  parts.  As  a  matter  of  fact,  the  weight  of  the 
car  is  more  than  enough  to  do  this  work  in  almost  every  case,  so  that  if 
the  car  could  be  made  lighter,  power  could  be  saved,  because  there  would 
be  less  dead  load  for  the  hydraulic  cylinder  to  lift  on  the  upward  trips. 
It  is  not  practicable  in  most  cases  to  reduce  the  weight  of  the  car,  but 
the  same  result  is  accomplished  by  adding  a  counterbalance  weight  on 
the  side  of  the  lifting  cylinder,  as  shown  at  W  in  Fig.  9. 

When  the  counterbalance  is  located  in  the  frame  of  the  traveling 
sheave,  as  shown  in  this  diagram,  its  weight  must  be  much  greater  than 
that  of  the  proportion  of  the  car  weight  it  is  intended  to  balance.  The 
difference  between  the  two  weights  will  depend  upon  the  gear  of  the 
elevator.  If  the  gear  is  two-to-one,  as  in  Fig.  9,  the  counterweight  will 
have  to  weigh  twice  as  much  as  the  portion  of  the  car  weight  that  it 
balances.  If  the  gear  were  three-to-one,  the  counterweight  would  weigh 
three  times  as  much,  and  for  a  four-to-one  gear,  four  times  as  much  as 
the  portion  of  the  car  it  balances.  From  this  it  can  be  seen  that  the 
weight  of  the  counterbalance  could  be  greatly  reduced  if  it  were  con- 
nected directly  with  the  car  by  means  of  ropes  running  over  an  overhead 
sheave,  as  shown  in  Fig.  10,  and  this  construction  is  commonly  used, 
although  the  whole  of  the  counterbalancing  is  very  rarely  done  in 
this  way. 

A  counterweight  connected  as  shown  at  w  in  Fig.  10  is  called  an 
independent  counterbalance,  and  it  possesses  some  advantages  as  well 
as  some  disadvantages.  One  advantage  of  an  independent  counter- 
balance is  that  it  saves  weight,  particularly  in  high-gear  machines,  as 
each  pound  in  the  counterweight  will  balance  one  pound  of  car,  while 
in  the  counterweight  W,  the  number  of  pounds  required  to  balance  one 
pound  of  car  is  equal  to  the  gear  of  the  machine ;  in  Fig.  10  it  would  be 
four  pounds. 


12 


HYDRAULIC  ELEVATORS 


Another  advantage  of  the  independent  counterbalance  is  that  the 
ropes  that  connect  the  weight  with  the  car  carry  a  portion  of  the  weight 
of  the  latter  equal  to  the  weight  of  the  counterbalance,  and  thus  take 
off  this  amount  of  strain  from  the  main  lifting  ropes,  arid  thereby  render 
the  elevator  that  much  safer. 

The  principal  objection  to  the  independent  counterbalance  is  that  it 
interferes  with  making  quick  stops  of  the  elevator.  This  objection  is 
not  very  great  in  the  case  of  slow-running  cars,  but  increases  rapidly 


FIG.  9 


FIG.   10 


as  the  car  speed  increases.  Looking  at  Fig.  10  it  can  be  seen  that  if  the 
car  were  stopped  suddenly  when  running  up,  the  momentum  of  the 
weight  w  would  tend  to  keep  it  running  down,  and  thus  draw  up  the 
car  and  slacken  the  ropes  passing  over  the  sheave  A.  It  can  also  be 
seen  that  if  the  weight  w  were  nearly  as  heavy  as  the  car,  the  tendency 
to  continue  on  the  downward  run  would  be  much  greater  than  if  its 
weight  were  only  a  small  portion  of  that  of  the  car.  The  energy  stored 
in  the  moving  parts  increases  as  the  square  of  the  velocity,  so  that  if  the 
car  speed  be  doubled,  the  energy  stored  in  the  counterweight  will  be 


COUNTERBALANCING — THE  HIGH-PRESSURE  SYSTEM  13 

quadrupled ;  hence,  the  higher  the  car  speed,  the  greater  the  objection  to 
putting  a  large  portion  of  the  weight  in  the  independent  counterbalance. 

Any  weight  used  as  a  counterbalance,  whether  located  at  w  or  at  W, 
will  oppose  the  stopping  of  the  car  on  the  upward  trip,  but  unless  the 
weight  is  equal  to  a  large  portion  of  that  of  the  car,  this  opposition  will 
amount  to  nothing  in  practice,  because  the  distance  in  which  a  car  can 
be  stopped  without  discomfort  to  the  passengers  is  much  greater  than 
that  through  which  it  would  be  carried  by  the  momentum  of  a  light 
counterbalance.  The  object  of  the  counterbalance  is  to  save  power  by 
reducing  the  weight  that  the  lifting  cylinder  has  to  raise,  and  this  object 
can  be  more  fully  realized  by  placing  the  weight  at  W  than  by  placing  it 
at  w,  because  in  this  way  the  weight  of  the  empty  car  can  be  more 
nearly  balanced.  Why  this  is  so  can  be  made  clear  by  a  simple  calcu- 
lation. 

Suppose  that  the  car  in  Fig.  10  weighs  1500  pounds,  and  that  if  all 
but  500  pounds  of  this  weight  be  balanced,  this  remainder  will  be  suffi- 
cient to  run  the  car  down  at  the  desired  velocity.  Now  if  all  this 
counterweight  be  put  in  an  independent  weight,  as  at  w,  we  will  require 
looo  pounds,  and  if  it  be  put  in  the  sheave  frame,  as  at  W,  we  will 
require  4000  pounds.  Suppose  that  the  car  speed  is  four  feet  per  second ; 
then,  since  the  energy  stored  in  the  moving  mass  is  proportional  to  the 
square  of  the  velocity,  w  would  be  equal  to  1000  X  4  X  4  =  16,000, 
while  with  the  counterweight  at  W  the  velocity  would  be  reduced  to 
one-fourth,  or  one  foot  per  second,  so  that  the  stored  energy  would  be 
4000  X  i  X  i  —  4000.  This  force  is  exerted  upon  the  ropes  that  pass 
under  the  traveling  sheaves  B  and  C,  so  that  the  force  acting  to  lift  the 
car  is  proportional  to  1000,  as  compared  with  16,000  in  the  other  case. 

As  the  force  tending  to  lift  the  car,  due  to  the  momentum  of  the 
counterweight,  is  sixteen  times  as  great  with  the  weight  in  w  as  with  it 
in  W,  it  follows  that  with  the  latter  counterbalance  a  shorter  stop  can 
be  made  than  with  the  former.  The  distance  required  to  make  a  stop 
with  the  weight  in  w  might  be  greater  than  that  desired,  and  the  only 
way  to  reduce  it  would  be  by  making  w  lighter.  It  is  evident  that  with 
the  counterbalance  at  W  the  unbalanced  weight  of  the  car  can  be  con- 
siderably less  than  with  the  weight  in  w,  and  that  the  difference  increase^ 
with  an  increase  in  car  speed,  and  with  higher  gear  ratios.  From  this 
it  will  be  evident  that  when  the  gear  of  the  elevator  is  high,  the 
momentum  of  the  counterweight  at  W  has  very  little  effect  upon  the 
quick  stopping  of  the  car,  and  on  that  account  the  weight  of  the  latter 
can  be  more  nearly  balanced  than  it  can  with  the  independent  weight 
at  w.  In  practice  the  total  counterbalance  is  put  partly  in  w  and  partly 
in  W,  the  object  of  so  doing  being  to  reduce  the  amount  of  iron  required, 


14  HYDRAULIC  ELEVATORS 

and  also  to  add  to  the  safety  of  the  elevator  system  by  providing  addi- 
tional ropes  to  hold  the  car,  and  by  taking  some  of  the  strain  from  the 
car-lifting  ropes.  Placing  the  counterbalance  weight,  or  a  part  of  it,  at 
W  does  not  increase  the  strain  on  the  lifting  ropes,  as  might  be  supposed 
on  first  considering  the  subject,  as  this  strain  is  determined  wholly  by  the 
weight  of  the  car  and  its  load. 

HIGH-PRESSURE    HYDRAULIC    ELEVATORS. 

The  elevators  so  far  considered  are  of  the  type  known  as  low  pressure, 
and  are  actuated  with  water  pressures  ranging  between  about  40  and  175 
pounds  per  square  inch.  In  the  early  days  of  hydraulic  elevators  the 
pressure  was  obtained  by  pumping  water  into  a  tank  located  upon  die 
roof  of  the  building,  and  as  a  column  of  water  of  one  square  inch  cross- 
section  weighs  about  0.434  of  a  pound  per  foot  of  hight,  the  pressure 
seldom  exceeded  50  pounds,  and  in  many  cases  was  as  low  as  30  pounds 
per  square  inch.  With  the  advent  of  high  buildings  greater  car  speed 
was  demanded,  and  this  necessitated  increasing  the  power  of  the  elevator 
machine.  This  increase  could  be  obtained  in  two  ways,  one  by  making 
the  cylinder  of  larger  diameter,  and  the  other  by  increasing  the  pressure. 
As  space  in  the  buildings  was  valuable,  the  latter  plan  was  adopted,  and 
in  order  to  obtain  the  increased  pressure,  a  closed  pressure  tank  was 
substituted  for  the  open  roof  tank.  The  pressure  tank  had  been  used 
years  before  the  time  of  high-power  elevators,  in  buildings  that  were  so 
low  that  the  pressure  obtained  from  an  open  tank  on  the  roof  was  not 
high  enough  to  keep  the  diameter  of  the  cylinder  within  reasonable 
bounds;  but  from  this  time  all  elevators  installed  in  high  buildings 
were  operated  with  water  drawn  from  pressure  tanks. 

The  general  introduction  of  the  pressure  tank  resulted  in  an  increase 
in  the  working  pressure  to  from  75  to  100  pounds.  By  this  increase  the 
size  of  the  cylinder,  the  tanks  and  the  piping  can  be  considerably  reduced, 
with  a  corresponding  saving  in  space  and  material.  With  the  continued 
increase  in  the  hight  of  buildings  the  pressure  has  been  increased,  so  that 
at  the  present  time  it  is  common  practice  to  use  pressures  up  to  180 
pounds  and  even  a  little  higher. 

With  the  view  to  reducing  the  size  of  the  cylinders  and  piping  still 
farther,  elevator  designers  decided  to  make  another  increase  in  pressure, 
but  this  time  a  clear  jump  was  made  from  180  to  700  and  800  pounds 
per  square  inch,  and  this  higher  pressure  is  now  carried  on  all  "high- 
pressure"  systems.  The  reason  why  a  jump  was  made  instead  of  increas- 
ing the  pressure  gradually  is  that  the  type  of  apparatus  used  for  the 
lower  pressures  is  not  adapted,  in  many  of  its  details,  to  much  higher 
pressures,  and  since  changes  in  these  details  were  required  it  was  con- 


COUNTERBALANCING — THE  HIGH-PRESSURE  SYSTEM  15 

sidered  advisable  to  increase  the  pressure  to  the  highest  point  that  had 
been  found  to  work  with  entire  success  in  other  fields  using  similar 
apparatus,  so  as  to  derive  the  greatest  possible  benefit  obtainable  from 
the  use  of  high  pressure. 

The  differences  between  high-pressure  and  low-pressure  elevator 
machines  can  be  pointed  out  by  the  aid  of  Fig.  n,  which  represents, 
elementarily,  a  high-pressure  machine  geared  two-to-one.  A  plunger 
replaces  the  piston  and  rods  of  the  low-pressure  machine,  and  the  water 
acts  to  force  it  out  of  the  cylinder  instead  of  drawing  it  in.  The 
advantage  of  this  construction  is  that  only  one  packing  is  required,  and 
that  is  located  in  the  end  of  the  cylinder,  where  it  is  easily  reached.  In 
the  low-pressure  cylinder,  the  piston  must  be  provided  with  a  packing, 
as  well  as  the  piston-rods,  but  as  the  diameter  of  the  cylinder  is  generally 
from  i o  to  20  inches,  there  is  ample  room  for  the  bolts  that  tighten  up 
the  packing  gland,  and  these  can  be  readily  got  at  when  the  piston  is  at 
the  end  of  the  cylinder. 

The  plunger  of  a  high-pressure  machine  is  finished  off  true  and  smooth, 
but  the  cylinder  is  only  finished  at  the  end,  this  part  being  a  casting 
provided  with  a  pipe  connection  at  the  side  and  a  stuffing-box  at  the 
outer  end.  This  end  casting  is  bored  to  fit  the  plunger.  The  body  of 
the  cylinder  is  made  of  extra  strong  steel  piping,  the  interior  diameter 
of  which  is  considerably  larger  than  the  outer  diameter  of  the  plunger. 
As  many  lengths  of  pipe  are  used  for  the  cylinder  as  may  be  required, 
and  these  are  generally  connected  together  by  flange  couplings. 

It  will  be  noticed  in  Fig.  n  that  the  cylinder  is  inverted  and  that  the 
plunger  forces  the  sheave  B  downward.  On  this  account  this  type  of 
machine  is  known  as  the  inverted  plunger.  Upright-plunger  machines 
geared  two-to-one  have  been  made,  but  higher  geared  machines  would 
be  impractical;  whereas  the  inverted  machine  can  be  made  of  any  gear 
desired,  and  in  reality  is  seldom  made  less  than  four-to-one.  In  a  two- 
to-one  inverted-plunger  machine  the  plunger  must  weigh  considerably 
less  than  double  the  weight  of  the  empty  car,  otherwise  the  latter  would 
not  be  able  to  run  down  and  lift  the  plunger  up  into  the  cylinder. 

If  the  cylinder  were  mounted  with  the  packed  end  up,  under  the 
sheave  B,  the  weight  of  the  plunger  would  have  to  pull  up  the  car  when 
loaded  to  its  maximum  capacity,  hence  the  plunger  would  have  to  weigh 
considerably  more  than  twice  as  much  as  the  car  with  its  maximum  load. 
From  this  it  is  evident  that  for  the  inverted-plunger  machine  the  weight 
of  the  plunger  is  very  much  less  than  for  the  upright  plunger.  For  any 
gear  greater  than  two-to-one  the  upright  plunger  would  not  be  desirable 
on  account  of  the  great  weight  of  the  plunger  necessary  to  lift  the  car. 
In  the  low-pressure  system  the  water  is  admitted  on  top  of  the  piston 


i6 


HYDRAULIC  ELEVATORS 


and  forces  it  down,  thereby  lifting  the  car,  but  in  the  upright  plunger 
the  water  is  admitted  under  the  plunger  and  forces  it  up,  thus  permitting 
the  car  to  run  down. 

Inverted-plunger  machines  are  generally  geared  from  four-to-one  to 
eight-to-one.  A  two-to-one  machine  cannot  be  used  for  very  high  lifts 
because  the  plunger  could  not  very  well  be  made  sufficiently  light.  Aside 
from  this  difficulty,  however,  it  is  cheaper  to  increase  the  gear  and  thus 
reduce  the  length  of  the  plunger  and  cylinder.  The  general  arrangement 
of  an  inverted-plunger  elevator  geared  six-to-one  is  shown  in  Fig.  12. 


FIG. 


FIG. 


As  will  be  noticed,  the  counterbalance  weight  is  partly  at  w  and  partly 
at  W.  For  medium  hight  buildings,  little  weight  has  to  be  placed  at  W, 
as  the  plunger,  sheaves  and  frame  are  nearly  heavy  enough,  especially 
as  in  such  buildings  the  gear  is  likely  to  be  not  more  than  four-to-one. 

The  advantages  of  the  high-pressure  system  are  that  considerably  less 
space  is  required  for  the  machinery  and  piping,  and  that  the  efficiency 
is  higher  than  that  of  the  low-pressure  system.  The  higher  efficiency  is 
due  to  the  fact  that  the  loss  of  energy  in  forcing  the  water  through  the 
pipes  can  be  greatly  reduced.  The  energy  required  to  force  water 
through  a  pipe  is  made  manifest  by  a  reduction,  or  drop,  in  the  pressure 


COUNTERBALANCING — THE  HIGH-PRESSURE  SYSTEM  I7 

between  the  point  where  the  water  enters  and  the  point  where  it  passes 
out.  The  higher  the  velocity  of  the  water,  the  greater  the  drop  in 
pressure,  the  increase  in  drop  being  about  as  the  square  of  the  velocity. 

With  a  low-pressure  system  operating  under  about  50  pounds,  it  might 
be  found  to  be  difficult  to  keep  the  loss  of  pressure  between  the  pressure 
tank  and  the  lifting  cylinder  below  20  pounds  if  the  connecting  piping 
were  long.  This  would  mean  a  loss  of  energy  of  40  per  cent.  If  the 
pressure  be  doubled,  one-half  the  amount  of  water  will  be  required, 
assuming  the  piston  and  valve  friction  to  remain  the  same.  As  one-half 
the  amount  of  water  is  used,  the  cross-section  of  the  pipes  can  be  reduced 
to  one-half  without  changing  the  velocity  of  the  water,  and  consequently 
without  increasing  the  loss  of  pressure  above  20  pounds.  From  this  it  is 
evident  that  the  pipe  loss  can  be  reduced  from  40  per  cent,  to  20  per  cent. 
by  increasing  the  pressure  from  50  to  100  pounds,  and  at  the  same  time 
the  pipes  can  be  reduced  to  one-half  the  cross-section. 

If  the  pressure  be  raised  to  800  pounds,  then  the  plunger  area  can  be 
reduced  to  one-eighth,  and  as  one-eighth  of  the  water  will  be  required, 
the  cross-section  of  the  pipes  can  be  reduced  to  one-eighth  without 
increasing  the  velocity  of  the  water,  and,  therefore,  without  increasing 
the  drop  in  pressure,  still  assuming  constant  friction.  By  increasing  the 
pressure  to  800  pounds,  and  reducing  the  pipes  to  one-eighth  of  the 
cross-section,  the  loss  of  pressure  in  the  pipes  is  not  increased  beyond 
the  original  20  pounds,  and  this  is  now  only  2^2  per  cent,  of  the  working 
pressure. 

The  foregoing  is  a  better  showing  than  could  be  made  in  practice 
because  the  loss  in  the  pipes  and  in  the  piston  friction  will  increase  with 
the  pressure  and  the  reduction  in  diameter,  so  that  the  size  of  the  cylinder 
and  pipes  cannot  be  reduced  as  much  as  these  calculations  show,  but  the 
sizes  would  not  have  to  be  increased  more  than  one-half,  or,  roughly,  the 
cross-sections  of  the  plunger  and  pipes  of  the  8oo-pound  system  would 
not  be  more  than  one-fifth  of  those  of  the  loo-pound  system. 

In  low-pressure  systems  the  piping  varies  between  about  3^2  inches 
and  7  inches  in  diameter,  and  such  piping  requires  considerable  space, 
especially  if  there  are  many  bends.  In  the  high-pressure  system  the 
piping  is  seldom  over  2^2  inches  in  diameter.  The  pipes  required  for 
low-pressure  systems  are  kept  down  in  size  somewhat  by  proportioning 
them  so  that  when  the  car  runs  at  the  maximum  velocity  it  will  only  lift 
about  five-eighths  of  the  maximum  load,  and  with  the  full  load  the 
velocity  is  about  one-half  of  the  maximum.  With  high-pressure  elevators 
the  pipes  can  be  made  so  as  to  maintain  the  maximum  car  speed  with 
nearly  the  maximum  load,  and  still  be  of  small  size,  because  the  drop  of 
pressure  in  the  pipes  is  so  small  a  percentage  of  the  total  pressure. 


CHAPTER  III 
PLUNGER  HYDRAULIC  ELEVATORS 

PLUNGER  ELEVATORS 

Fig.  13  illustrates  in  its  simplest  form  what  is  known  as  the  plunger 
elevator.  Elevators  of  this  type  have  been  made  in  this  country  for 
many  years  for  short  rises,  but  within  the  last  seven  or  eight  years  they 
have  come  into  use  for  all  classes  of  service  and  for  buildings  of  any 
hight.  In  Europe  plunger  elevators  have  been  used  for  many  years,  but 
generally  for  moderate  rises — in  fact,  what  we  call  high  rises  in  this 
country  are  practically  unknown  in  Europe,  where  buildings  over  one 
hundred  feet  high  are  exceptional.  At  the  present  time  there  are  a  large 
number  of  plunger  elevators  in  operation  in  New  York  that  rise  over  200 
feet,  and  in  one  building  they  rise  about  300  feet.  Fig.  13  illustrates 
what  is  commonly  called  a  sidewalk  elevator,  which  is  arranged  to  run 
the  platform  A  up  from  the  level  of  the  basement  floor  B  to  the  sidewalk 
D.  All  this  diagram  requires  to  complete  it  is  an  operating  valve  in  the 
pipe  /  and  suitable  guides  for  the  platform  to  keep  the  plunger  P  in  line 
with  the  cylinder  C. 

The  construction  of  this  type  of  elevator  is  very  simple.  The  cylinder 
is  made  of  one  or  more  lengths  of  steel  pipe,  the  lower  end  being  closed 
by  a  suitable  cap  and  the  upper  end  being  finished  off  with  a  casting  bored 
to  take  the  plunger,  and  provided  with  a  stuffing-box  and  an  inlet  at  the 
side  for  connection  with  the  water-supply  pipe.  The  cylinder  is  set  in  a 
hole  in  the  ground,  and  is  made  of  a  length  a  few  feet  greater  than  the 
rise  of  the  elevator  car.  The  plunger  is  made  of  steel  pipe  and  is  turned 
true  and  smooth  to  fit  the  bore  of  the  top  casting  of  the  cylinder.  When 
the  rise  is  greater  than  one  length  of  the  piping  used,  two  or  more 
lengths  are  joined  by  means  of  internal  sleeves  made  long  enough  to  give 
the  joints  as  much  strength  as  the  body  of  the  pipe. 

The  simple  arrangement  of  Fig.  13  is  very  satisfactory  for  short  rises, 
but  for  any  considerable  hight  it  is  necessary  to  counterbalance  the  car  in 
order  to  reduce  the  pressure  required  to  operate  the  elevator.  The 
plungers  are  as  a  rule  made  of  six-inch  pipe,  which  when  turned  weighs 
about  1 6  pounds  per  foot  for  standard  pipe,  and  about  25  pounds  per 
foot  for  extra  strong,  which  is  used  for  very  heavy  duty.  If  the  rise  of 
the  car  is  200  feet,  and  the  plunger  is  made  of  standard  pipe,  it  will 
weigh  about  3500  pounds,  with  the  end  castings.  If  the  car  is  of  equal 
weight,  which  is  not  very  far  from  the  average,  the  total  weight  will  be 

18 


PLUNGER  HYDRAULIC  ELEVATORS 


7000  pounds,  which  is  a  considerable  load  to  lift,  especially  if  the  speed 
is  400  or  500  feet  per  minute.  If  a  counterbalance  of  5000  pounds  is 
provided  the  power  required  to  operate  the  elevator  will  be  greatly 
reduced. 

The  counterbalance  can  be  arranged  in  either  of  two  ways,  one  of 
which  is  illustrated  in  Fig.  14  and  the  other  in  Fig.  15.  In  the  first 
arrangement  the  gear  between  the  car  and  counterweight  is  one-to-one, 
and  in  the  second  it  is  two-to-one.  Each  arrangement  has  its  advantages 


FIG.  13  FIG.   14  FIG.  15 

and  disadvantages,  and  the  question  as  to  which  is  the  better  is  probably  a 
matter  of  individual  opinion.  The  plan  in  Fig.  14  is  simple  and  requires 
less  weight  than  the  two-to-one  gear  of  Fig.  15;  but  to  offset  this  there 
is  the  fact  that  to  be  able  to  make  a  stop  on  the  up  trip  within  a  certain 
distance,  the  unbalanced  weight  of  the  car  must  be  greater.  The  reason 
for  this  difference  is  the  same  as  that  given  in  the  discussion  of  Fig.  10, 
Chapter  II. 

The  counterbalance  serves  not  only  to  reduce  the  amount  of  power 
required  to  operate  the  elevator,  but  also  to  reduce  the  compression  stress 


2O  HYDRAULIC  ELEVATORS 

that  the  plunger  is  subjected  to,  and  thus  to  prevent  the  buckling  of  the 
latter  when  stopped  suddenly  on  a  downward  stroke.  Taking  the  figures 
for  the  rise  and  the  weight  of  car  and  counterweight  previously  given,  it 
will  be  evident  that  if  the  car  is  empty  it  will  fall  short  1500  pounds  of 
balancing  the  counterweight,  therefore  the  latter  actually  holds  up  1500 
pounds  of  the  plunger.  This  means  that  if  the  car  is  empty,  the  upper 
end  of  the  plunger  is  subjected  to -tension  and  not  to  compression.  At  a 
point  about  90  feet  from  the  top  there  will  be  no  stress  in  the  plunger, 
and  below  this  point  a  compression  stress  will  appear  which  will  increase 
at  the  rate  of  about  16  pounds  per  foot. 

If  a  load  of  1500  pounds  is  in  the  car,  then  the  point  where  there  is 
no  stress  in  the  plunger  will  be  at  the  upper  end.  With  a  load  of  2500 
pounds  in  the  car,  which  is  about  the  maximum  carried  in  passenger 
elevators  for  the  average  office  building,  the  compression  stress  at  the 
top  of  the  plunger  will  be  1000  pounds,  and  will  increase  below  this 
point  at  the  rate  of  about  16  pounds  per  foot,  becoming  about  2600  at 
the  center  point  and  4200  pounds  at  the  bottom  of  the  plunger.  This  is 
the  reason  why  the  plunger,  although  only  6l/2  inches  in  diameter,  will 
not  buckle  under  the  load  even  if  made  300  feet  long.  Another  fact  that 
accounts  for  the  rigidity  of  the  plunger  is  that  only  the  portion  that  is 
in  the  air,  above  the  top  of  the  cylinder,  is  liable  to  buckle,  and  the  com- 
pression stress  in  this  decreases  as  the  car  rises,  owing  to  the  fact  that 
the  passengers  leave  the  car  at  the  various  floors  as  the  elevator  ascends 
and  when  the  top  of  the  building  is  reached  the  car  is  nearly  if  not 
entirely  empty. 

The  compression  stress  that  the  plunger  is  subjected  to  could  be 
reduced  by  increasing  the  counterbalance,  but  if  this  were  done  the 
distance  required  to  make  a  stop  would  be  increased.  The  unbalanced 
weight  of  the  car  has  to  be  determined  with  reference  to  the  distance 
in  which  stops  must  be  made,  and  also  with  reference  to  the  speed  of 
the  car.  If  the  stopping  distance  remains  the  same,  the  counterweight 
must  be  reduced  as  the  speed  is  increased,  or  the  weight  may  remain 
unchanged  if  the  stopping  distance  is  increased. 

The  stopping  distance  is  controlled  by  setting  the  valve-operating 
mechanism  so  that  the  flow  of  water  cannot  be  stopped  entirely  in  less 
than  a  certain  time;  while  the  operator  may  make  a  slower  stop,  he 
cannot  make  a  quicker  one.  The  effect  of  making  too  quick  a  stop  on 
the  up  trip  would  be  to  lift  the  plunger  off  the  water  in  the  cylinder  a 
few  inches;  the  vacuum  produced  would  assist  in  bringing  the  car  to  a 
state  of  rest.  On  the  down  trip  the  effect  of  too  quick  a  stop  would  be 
to  put  an  excessive  compression  stress  in  the  plunger. 


CHAPTER  IV 

HORIZONTAL  CYLINDER  MACHINES— "PUSHING"  AND 
"PULLING"  TYPES 

Horizontal-cylinder  elevators  are  divided  into  "pushing"  and  "pulling" 
machines.  A  "pushing"  machine  is  one  in  which  the  piston  pushes  the 
traveling  sheaves  away  from  the  cylinder,  and  a  "pulling"  machine  is 
one  in  which  the  piston  pulls  the  traveling  sheaves  toward  the  cylinder. 
In  Fig.  16  a  pulling  machine  is  illustrated.  In  this  type  of  elevator, 
when  the  car  is  at  the  bottom  of  the  well  the  traveling  sheaves  are  at  D, 
and  the  piston  is  at  the  front  end  of  the  cylinder  G.  When  the  car 
ascends  to  the  top  of  the  building,  the  traveling  sheaves  and  cables  reach 
the  position  shown  by  the  broken  lines.  It  will  be  evident  that  the 
pressure  water  enters  the  cylinder  between  the  piston  and  the  cylinder- 
head  and  forces  the  piston  to  the  right,  and  through  the  piston-rod  the 
traveling  sheaves  D  are  pulled  toward  the  cylinder.  The  weight  of  these 
sheaves  is  taken  by  the  roller  E  and  guides  F.  The  mode  of  operation 
of  a  pushing  machine  is  shown  in  Fig.  17.  Here  it  will  be  obvious  that 
the  water  entering  the  cylinder  between  the  piston  and  the  cylinder-head 
forces  the  piston  to  the  right  and,  through  the  rod,  the  traveling  sheaves 
D  are  pushed  away  from  the  cylinder  and  reach  the  position  indicated 
by  the  dotted  lines  when  the  elevator  car  reaches  the  top  of  the  building. 

Which  of  these  two  designs  is  the  better,  it  is  difficult  to  say.  The 
pushing  machine  obviates  the  use  of  a  stuffing-box  around  the  piston-rod, 
but  this  is  offset  by  the  fact  that  the  diameter  of  the  sheaves  must  be 
greater  than,  that  of  the  outside  of  the  cylinder,  in  order  that  the  lifting 
ropes  may  clear  the  latter;  this  can  be  readily  seen  from  Fig.  17.  In  both 
designs,  the  stationary 'sheaves  B  have  to  be  placed  at  the  side  of  the 
elevator  well,  in  order  that  the  lifting  ropes  may  run  up  in  the  space 
between  the  wall  of  the  well  and  the  side  of  the  car.  On  this  account 
the  cylinder  of  the  pushing  machine  is  located  nearer  the  well  than  that 
of  the  other  type.  In  some  buildings  the  pumps,  tanks,  etc.,  are  located 
near  the  elevator  well,  but  in  others  they  are  some  distance  away,  so 
that  in  some  cases  it  is  advantageous  to  have  the  cylinder  near  the 
elevator,  while  in  others  it  is  not,  as  it  is  always  desirable  to  have  it  as 
near  to  the  pumping  system  as  possible,  to  reduce  the  length  of  the 

21 


22 


HYDRAULIC  ELEVATORS 


pipe  connections.  The  pulling  machine  is  not  as  well  adapted  to  high 
pressures  as  the  pushing  machine,  on  account  of  the  packing  around  the 
piston-rod,  and  on  that  accountable  latter  type  is  the  only  one  that  has 
been  used  in  high-pressure  systems. 

Horizontal  cylinders  are  not  provided  with  circulating  pipes  because 
none  is  required,  both  ends  of  the  cylinder  being  on  the  same  level.  The 
pressure  water  passes  in  and  out  of  one  end  of  the  cylinder  only,  and 
no  water  reaches  the  other  end  except  what  leaks  by  the  piston. 

Horizontal-cylinder   elevator   systems    are   counterbalanced    with   an 


FIG.  I? 


FIG.  16 


independent  weight,  as  shown  at  w  in  Fig.  16.  As  can  be  readily  seen, 
no  counterbalancing  can  be  done  in  the  traveling-sheave  frame,  because 
this  moves  in  a  horizontal  direction.  Horizontal  machines  are  geared 
from  six-to-one  to  twelve-to-one.  The  sheaves  by  means  of  which 
the  gearing  is  effected  are  not  located  one  behind  the  other,  as  in  the 
vertical  machines,  but  are  placed  side  by  side  on  axles  that  are  at  right 
angles  to  the  axis  of  the  piston-rod,  as  indicated  in  Figs.  16  and  17. 
The  number  of  lifting  ropes  used  is  two,  and  each  one  of  these  passes 


HORIZONTAL  CYLINDER  MACHINES  23 

around  a  set  of  sheaves  on  one  side  of  the  center  line  of  the  piston-rod, 
so  that  the  pull  of  the  ropes  may  not  act  to  twist  the  sheave  axle  out  of 
position.  When  it  is  desired  to  obtain  a  gear  higher  than  twelve-to-one, 
the  general  practice  is  to  use  a  machine  of  one-half  the  desired  gear,  and 
double  this  by  using  a  traveling  sheave  in  the  elevator  well  in  the  manner 
illustrated  in  Fig.  18.  With  this  arrangement,  if  the  gear  at  the  cylinder 


FIG.  18 

is  eight-to-one,  the  gear  between  the  car  and  the  piston  will  be  sixteen- 
to-one.  With  this  construction  the  counterweight  can  be  placed  in  the 
sheave  frame,  as  shown  at  W ,  and  the  advantage  of  this  method  of 
counterbalancing  realized. 

As  to  a  comparison  of  the  vertical  and  horizontal  machines,  it  is 
difficult  to  say  which  is  the  better,  because  the  difference  between  them 
is  very  slight.  In  the  horizontal  machine  the  lower  side  of  the  piston 
and  cylinder  are  subjected  to  a  wear  from  which  the  vertical  cylinder  is 
free,  but  this  objection  is  of  less  importance  in  elevator  than  in  steam- 
engine  cylinders,  as  the  latter  are  worn  more  in  a  lifetime.  In  the 
vertical-cylinder  machine  the  piston  friction  is  greater  because  the  stroke 
is  longer,  but  to  offset  this  in  the  horizontal  machine  the  sheave-and-rope 


24  HYDRAULIC  ELEVATORS 

friction  is  greater  on  account  of  the  higher  gear.  In  practice  the  type 
of  machine  used  is  in  most  cases  determined  by  the  dimensions  of  the 
building.  If  the  building  covers  a  good  deal  of  ground,  and  the  space 
in  the  basement  is  not  as  valuable  as  elsewhere,  the  horizontal  machine 
is  used.  If  the  building  is  high  and  stands  on  a  small  lot,  the  vertical 
type  is  preferable,  and  if  the  floor  space  is  very  small,  it  may  be  the 
only  type  that  can  be  used  on  account  of  the  length  of  the  horizontal 
machine  being  greater  than  the  greatest  dimension  of  the  building  site. 

When  horizontal  machines  are  installed  in  buildings  where  the  space 
is  contracted,  it  is  common  practice  to  stack  the  machines  one  on  top  of 
the  other,  making  what  are  called  double-  and  triple-deckers.  When 
vertical  cylinders  are  used,  they  are  sometimes  located  in  the  elevator 
well  at  one  side  of  the  space  in  which  the  elevator  travels,  but  this 
arrangement  is  not  desirable  because  the  noise  made  by  the  water 
passing  in  and  out  of  the  cylinder  is  objectionable;  moreover,  if  the 
cylinder  springs  a  leak,  which  is  not  a  rare  occurrence,  the  passengers 
in  the  car  are  liable  to  receive  an  unwelcome  shower  bath.  The  best 
practice  is  to  locate  vertical  cylinders  in  a  separate  well  so  located  that 
the  lifting  ropes  may  be  run  directly  to  the  elevator  cars  over  sheaves 
at  the  top  of  the  building. 


CHAPTER  V 

COUNTERBALANCING  THE  LIFTING  ROPES  OF  ELEVATOR 

CARS 

When  an -elevator  car  is  at  the  bottom  of  the  well,  the  weight  that 
has  to  be  lifted  comprises  that  of  the  car,  its  load  and  the  ropes  hanging 
in  the  elevator  well  above  the  car.  When  the  car  is  at  the  top  of  the 
building,  only  the  car  and  its  load  have  to  be  lifted.  This  being  the  case, 
it  is  evident  that  if  the  counterbalahce  is  such  that  when  the  car  is  at 
the  top  of  the  building  all  its  weight  except  500  pounds  is  balanced,  then 
when  the  car  is  at  the  bottom  floor  the  unbalanced  weight  will  be  500 
pounds  plus  the  weight  of  the  lifting  ropes  hanging  above  it.  If  these 
ropes  were  light  it  would  not  be  worth  while  to  consider  their  weight, 
but  as  they  are  not  light,  the  power  required  to  operate  the  elevator  can 
be  considerably  reduced  by  providing  means  to  compensate  for  the 
varying  weight  of  ropes  that  must  be  lifted  when  the  car  is  at  different 
points  in  the  elevator  well.  Why  this  is  true,  and  how  the  weight  of 
the  ropes  is  compensated  for,  can  be  made  clear  by  the  aid  of  Fig.  19. 

In  Fig.  19  let  the  top  position  of  the  car  be  200  feet  above  the  lower 
position.  If  the  elevator  is  connected  in  the  way  shown  it  may  have 
four  or  six  lifting  ropes,  which  as  a  rule  are  ^  of  an  inch  in  diameter. 
These  ropes  weigh  about  0.7  of  a  pound  per  foot,  which  for  four  ropes 
makes  2.8,  and  for  six  ropes  4.2  pounds;  for  200  feet,  therefore,  the 
weight  will  be  560  pounds  for  four  ropes  or  840  pounds  for  six  ropes. 
If,  when  the  car  is  at  the  top,  its  unbalanced  weight  is  500  pounds,  in 
the  bottom  position  it  will  be  500  +  560  =  1060  pounds  with  four  ropes, 
or  500-1-840=  1340  pounds  with  six  lifting  ropes.  If  the  maximum 
load  the  car  is  designed  to  lift  is  2000  pounds,  the  average  will  be  about 
1000,  so  that  the  work  the  elevator  machine  has  to  do  when  the  car  is 
approaching  the  topmost  position  is  to  lift  1500  pounds,  but  when  it 
starts  from  the  bottom  position  the  load  that  must  be  lifted  is  2060 
pounds  if  there  are  four  lifting  ropes,  or  2340  pounds  if  there  are  six 
ropes.  It  will  be  evident  that  if  the  weight  of  the  ropes  could  be 
eliminated,  about  27  per  cent,  of  the  power  could  be  saved  if  there  were 
four  ropes,  or  about  36  per  cent,  if  there  were  six  ropes.  As  a  matter 
of  fact,  the  saving  would  be  more,  for,  as  may  be  seen  from  Fig.  19, 
when  the  car  reaches  the  upper  position,  the  traveling  sheave  M  will  be 

25 


26 


HYDRAULIC  ELEVATORS 


in  the  lower  position  N,  and  the  length  of  the  ropes  from  G  to  H  will 
be  added  to  the  weight  of  the  counterbalance;  therefore,  this  weight 
would  have  to  be  deducted  from  the  counterbalance  in  order  not  to  have 
less  than  500  pounds  of  unbalanced  weight  when  the  car  is  in  the  top 
position. 


FIG.  19 


FIG.  20 


The  weight  of  the  ropes  cannot  be  eliminated,  but 'the  same  result 
can  be  obtained  by  using  a  chain  /  secured  to  the  side  of  the  elevator 
well  at  a  point  K  a  trifle  above  the  middle  point,  the  other  end  being 
fastened  to  the  underside  of  the  car.  When  the  car  is  at  the  bottom,  the 
chain  hangs  from  the  point  K,  but  as  the  car  ascends,  part  of  the  weight 
of  the  chain  hangs  on  the  car,  and  when  the  car  reaches  the  top  position 
all  of  the  weight  of  the  chain  will  hang  from  it.  Now  to  make  this  chain 
compensate  for  the  varying  weight  of  the  lifting  ropes  all  that  is  neces- 


COUNTERBALANCING  THE  LIFTING  ROPES  OF  ELEVATOR  CARS      27 

sary  is  to  make  it  weigh  as  much  as  the  200  feet  of  ropes  that  hang  in 
the  elevator  well  when  the  car  is  at  the  bottom  plus  the  length  of  ropes 
from  G  to  //  when  the  car  is  at  the  top.  If  the  elevator  is  geared  two- 
to-one,  as  in  Fig.  19,  the  distance  from  G  to  H  will  be  100  feet,  or  one- 
half  the  rise  of  the  car.  For  a  three-to-one  gear,  G — H  will  be  equal  to 
one-third  the  rise  of  car,  and  so  on  for  any  other  gear. 

When  the  compensating  chain  is  secured  to  the  bottom  of  the  car,  its 
weight  acts  in  opposition  to  that  of  the  counterbalance,  and  the  latter 
must  be  increased  in  weight  sufficiently  to  compensate  for  the  weight  of 
the  chain.  The  chain  can  be  attached  to  the  underside  of  the  counter- 
balance in  some  cases,  and  then  its  weight  acts  with  the  counterbalance 
so  that  the  latter  can  be  reduced  in  a  corresponding  amount. 

The  best  way  to  connect  the  compensating  chain  is  to  attach  one  end 
to  the  underside  of  the  car,  and  the  other  to  the  counterweight,  as  in 
Fig.  20.  With  this  arrangement  the  weight  of  chain  can  be  reduced  to 
one-half,  because  when  the  car  is  at  the  bottom  of  the  well  the  chain 
hangs  on  the  counterweight,  and  when  the  car  is  at  the  top,  the  chain 
hangs  from  the  car.  In  practice,  the  chain  is  connected  with  the  car 
only  in  almost  every  case,  because  there  is  not  sufficient  space  in  the 
path  of  the  counterbalance  for  it  to  hang  freely  without  danger  of  being 
caught. 

In  a  horizontal  elevator  with  an  independent  counterbalance,  as 
shown  in  Fig.  16,  the  counterbalance  ropes  add  their  whole  weight  to  the 
counterbalance  when  the  car  is  at  the  top  of  the  building,  and  their 
whole  weight  to  the  car  when  the  latter  is  at  the  bottom;  hence,  the 
weight  of  chain  required  to  compensate  for  the  counterbalance  ropes  is 
double  the  weight  of  these  ropes,  and  to  compensate  for  the  lifting  ropes 
a  weight  equal  to  that  of  those  ropes  must  be  added. 

In  practice,  usually  two  compensating  chains  are  used,  and  although 
they  function  perfectly  and  never  give  trouble,  they  are  somewhat 
unsightly,  and  on  that  account  a  method  of  compensating  for  the  varying 
weight  of  the  ropes  by  means  of  a  column  of  water  has  been  used  in 
some  cases.  This  arrangement  is  illustrated  in  Fig.  21.  When  the 
piston  descends  in  the  cylinder  C  the  water  under  the  piston  is  forced 
up  into  the  stand-pipe  B,  and  this  exerts  a  back  pressure  that  increases 
as  the  piston  travels  downward.  When  the  piston  is  at  the  top  of  the 
cylinder,  the  car  is  at  the  bottom  of  the  building  and,  therefore,  the 
weight  of  the  ropes  has  to  be  lifted.  At  this  time,  however,  the  water 
in  the  stand-pipe  B  is  at  the  level  E,  so  that  there  is  no  back  pressure, 
and  as  a  result  the  lifting  force  is  equal  to  the  full  pressure  of  the  water 
admitted  above  the  piston.  When  the  car  is  at  the  top  of  the  building 
the  piston  is  at  the  bottom  of  the  cylinder,  and  the  water  in  the  stand-pipe 


28 


HYDRAULIC  ELEVATORS 


is  forced  up  to  the  level  Df  so  that  there  is  a  back  pressure  acting  on 
the  underside  of  the  piston  equal  to  the  head  E — D. 

To  make  this  arrangement  compensate  fully  for  the  varying  weight 
of  the  ropes  all  that  is  necessary  is  to  make  the  internal  diameter  of  the 
stand-pipe  B  such  that  when  the  piston  reaches  the  lowest  position  in 


FIG.  21 


the  cylinder  the  weight  of  the  water  in  B  will  be  just  sufficient  to  offset 
the  weight  of  the  ropes.  It  will  be  noticed  that  this  back  pressure  pushes 
upward  against  the  piston  and  thus  holds  up  a  certain  portion  of  the 
counterweight,  so  that  a  weight  can  be  used  that  would  be  sufficient  to 
overbalance  the  car  entirely  when  the  latter  is  at  the  top  of  the  building 
if  it  were  not  for  the  assistance  given  by  the  back  pressure  of  the  water 


COUNTERBALANCING  THE  LIFTING  ROPES  OF  ELEVATOR  CARS      29 

in  the  stand-pipe.  It  might  be  supposed  that  to  obtain  the  exact  weight 
of  water  required  it  would  be  necessary  to  make  the  stand-pipe  of  cast- 
iron  sections  and  bore  them  accurately  to  the  proper  size,  but  in  practice 
it  has  been  found  wherever  this  arrangement  has  been  installed  that 
ordinary  steam  pipes  can  be  used  that  are  near  enough  to  the  proper 
diameter  to  compensate  for  the  weight  of  the  ropes  within  less  than 
four  or  five  per  cent.  The  water  supply  under  the  cylinder  is  kept  up 
to  the  proper  amount  by  what  leaks  past  the  piston,  and  in  fact  an 
overflow  is  provided  at  the  upper  level  in  the  stand-pipe  to  carry  off  the 
excess.  This  arrangement,  of  course,  cannot  be  used  with  a  circulating 
pipe,  and  it  may  also  be  mentioned,  that  the  lower  level  E  cannot  be 
more  than  about  32  feet  below  the  underside  of  the  piston  when  the 
latter  is  in  the  highest  position. 


CHAPTER  VI 

GENERAL  ARRANGEMENT  OF  HYDRAULIC  ELEVATOR 

SYSTEMS 

There  are  several  ways  in  which  hydraulic  elevator  systems  are 
arranged,  and  these  are  shown  in  the  sketches  from  Fig.  22  to  Fig.  24. 
The  first  one  is  what  is  called  the  gravity  system,  and  is  the  type  first 
used.  A  tank  is  placed  on  the  roof  of  the  building,  and  the  water  is 
pumped  into  this  to  obtain  the  necessary  head  to  actuate  the  piston  in 
the  lifting  cylinder  C.  Water  passes  from  this  tank  through  the  pipe  A 
to  the  upper  end  of  the  cylinder,  and  forces  the  piston  downward  and 
the  car  upward.  On  the  return  stroke  of  the  piston  the  water  circulates 
through  pipe  B  from  the  upper  to  the  lower  end  of  the  cylinder.  On 
the  next  down  stroke,  the  upper  end  of  the  cylinder  is  again  filled  from 
the  pipe  A,  and  the  water  under  the  piston  passes  out  through  the  pipe  D 
to  the  discharge  tank,  whence  it  is  raised  to  the  roof  tank  by  the  pump. 
The  pump  is  stopped  and  started  automatically  by  a  float  in  the  roof 
tank,  which  closes  the  starting  valve  of  the  pump  when  the  water 
reaches  the  high  level,  and  opens  it  when  the  water  is  drained  to  the 
low  level. 

The  system  shown  in  Fig.  23  is  known  as  the  pressure-tank  system, 
and  differs  from  Fig.  22  only  in  having  a  pressure  tank  in  place  of  the 
roof  tank.  With  the  gravity  system  the  pressure  is  generally  between 
25  and  40  pounds  per  square  inch,  according  to  the  hight  of  the  building. 
With  the  pressure-tank  system  the  range  is  between  50  and  200  pounds. 
In  the  pressure-tank  system  the  pump  is  controlled  by  a  pressure  regu- 
lator that  is  connected  with  the  pressure  tank. 

Fig.  24  is  a  system  that  has  been  installed  in  a  number  of  large 
buildings  by  the  Otis  Elevator  Company,  and  is  known  as  the  double- 
power  system.  There  are  two  pressure  tanks,  one  carrying  about  double 
the  pressure  of  the  other.  The  main  pump  delivers  water  into  the  low- 
pressure  tank,  and  a  booster  pump  draws  from  this  tank  and  delivers 
into  the  high-pressure  one.  The  elevator  cylinder  operating  valve  is 
made  so  that  when  opened  part  of  the  way  it  draws  water  from  the 
low-pressure  pipe  only,  and  when  opened  further  it  draws  from  both 
the  low-pressure  and  high-pressure  pipes.  If  the  load  in  the  car  is  light, 
the  desired  speed  can  be  obtained  with  the  low-pressure  water  alone, 

30 


GENERAL  ARRANGEMENT  OF  HYDRAULIC  ELEVATOR  SYSTEMS        31 

but  if  the  load  is  so  heavy  that  the  low  pressure  will  not  give  the  desired 
speed,  the  valve  is  opened  further,  and  then  high-pressure  water  runs  in 
to  help  the  low  pressure  and  gives  the  proper  velocity  of  car.  A  check- 
valve  is  included  in  the  low-pressure  pipe  to  prevent  the  high-pressure 
water  from  running  back  into  the  low-pressure  tank;  but  unless  the  load 


.x~^\ 


^B 

•n 

c 

Disclmrgei 
Tank     ;! 

^ 

i  i  . 
v 

FIG.     22 


FIG.  23 


is  very  nearly  up  to  the  maximum,  water  will  be  drawn  from  both  tanks, 
This  system  was  devised  in  order  to  make  the  power  used  by  the  elevator 
more  nearly  proportional  to  the  loads  lifted.  When  the  low-pressure 
water  is  used,  the  power  consumption  is  about  one-half  that  when  the 
high  pressure  is  used.  For  loads  greater  than  one-half  the  maximum, 
the  power  required  is  more  than  one-half,  but  less  than  the  whole  amount, 


32  HYDRAULIC  ELEVATORS 

unless  the  load  is  very  near  to  the  maximum,  in  which  case  all  the  water 
used  will  be  drawn  from  the  high-pressure  tank. 

The  three  systems  illustrated  in  Figs.  22  to  24  are  of  the  low-pressure 
type,  and  can  be  used  to  operate  one  or  any  number  of  elevators.    The 


FIG.  24 


high-pressure  system  described  in  Chapter  II  is  arranged  in  a  manner 
similar  to  Fig.  22  arid  is  fully  explained  in  Chapters  XXIX  to  XXXIV. 


CHAPTER  VII 
VERTICAL  HYDRAULIC  ELEVATORS 

SIMPLE  LOW-PRESSURE  VERTICAL  TYPE  OTIS  ELEVATOR   WITH    HAND-ROPE 

CONTROL 

The  fundamental  principles  of  the  different  types  of  hydraulic 
elevators  having  been  discussed  in  the  preceding  chapters,  the  construc- 
tional features  of  each  type  will  next  be  considered.  This  chapter  is 
devoted  to  the  simplest  form  of  vertical  low-pressure  elevator,  such  as 
is  installed  in  buildings  from  five  to  seven  stories  high.  An  elevator 
of  this  class  is  very  clearly  represented  in  Fig.  25,  which  shows  an 
Otis  machine  geared  two-to-one.  Looking  at  this  illustration,  it  will  be 
seen  that  the  general  arrangement  is  the  same  as  that  of  diagram 
Fig.  3>  and  from  this  fact  it  might  be  inferred  that  the  elevator  is  not 
counterbalanced.  This,  however,  is  not  the  case ;  a  counterbalance  is 
used,  but  it  is  placed  within  the  cylinder,  resting  on  top  of  the  piston. 
This  construction  is  very  common  with  two-to-one  machines,  and  even 
with  higher  gears.  Generally  a  portion  of  the  counterbalance  is  placed 
on  top  of  the  piston,  so  that  in  such  machines  the  counterbalance  weight 
is  divided  into  three  parts,  one  being  within  the  cylinder,  one  in  the 
traveling  sheave  frame,  and  one  constituting  the  independent  counter- 
balance. 

It  will  be  noticed  in  Fig.  25  that  there  are  two  piston-rods  R.  This 
construction  was  adopted  in  the  early  days  of  hydraulic  elevators  par- 
tially to  increase  the  safety  of  the  apparatus,  but  principally  to  prevent 
the  traveling  sheave  B  from  twisting  around.  The  ropes  tend  to  hold 
the  sheave  from  twisting,  but  they  will  not  prevent  slight  movements, 
while  the  double  piston-rods  will.  Now  and  for  several  years  past, 
however,  the  frame  of  the  traveling  sheave  has  been  made  in  the  form 
of  a  cross-head  running  in  stationary  guides,  thus  effectually  preventing 
any  side  movement  of  the  sheave.  With  this  construction  the  main 
benefit  of  the  double  piston-rods  is  additional  safety;  while  it  is  possible 
for  one  rod  to  break  or  become  loose,  it  is  practically  impossible  for 
both  to  give  way  at  the  same  time. 

The  arrangement  of  the  cylinder  C,  the  circulating  pipe  K  and  the 
valve  V ,  in  Fig.  25,  is  the  same  as  in  the  diagram  Fig.  7,  even  the  inlet  / 

33 


FIG.  2 


OTIS   VERTICAL  HYDRAULIC  ELEVATOR   FOR  MODERATE   SPEEDS 


VERTICAL  HYDRAULIC  ELEVATORS  35 

being  similarly  situated.  The  small  pipe  c  is  for  the  purpose  of  carrying 
off  the  drip  from  the  upper  side  of  the  top  cylinder  head,  ordinarily, 
and  also  for  the  purpose  of  draining  the  water  from  the  upper  end  of 
the  cylinder,  in  cases  where  it  is  necessary  to  run  the  piston  to  the  top  of 
the  cylinder  to  renew  or  adjust  the  packing.  Some  cylinders  are  arranged 
to  be  packed  from  the  upper  end  and  others  from  the  lower  end,  the 
latter  design  being  the  one  generally  used  in  modern  machines.  As  will  be 
noticed,  the  pipe  c  connects  at  the  bottom  of  the  cylinder  with  other  pipes 
that  connect  with  the  valve  chest  and  the  lower  end  of  the  cylinder.  All 
these  pipes  are  either  to  carry  off  the  drip  or  to  draw  water  from  the 
various  parts  of  the  cylinder  and  valve  chest  when  desired.  Globe  valves 
are  placed  in  the  drainage  pipes  so  as  to  keep  them  closed  normally. 

The  elevator  is  operated  by  the  movement  of  the  hand  rope  n,  which 
passes  around  a  sheave,  at  the  side  of  the  valve  chest,  which  moves  the 
valve  through  a  rack  and  pinion  gear,  thence  under  two  small  sheaves  at 
the  bottom  of  the  elevator  well,  and  from  there  upward  to  the  top  of 
the  well  over  another  small  sheave.  One  side  of  the  hand  rope  passes 
through  the  elevator  car,  and  by  pulling  this  side  up  the  operator  causes 
the  car  to  descend,  while  by  pulling  it  down  he  causes  the  car  to  ascend. 
It  will  be  noticed  that  near  the  top  and  bottom  of  the  well  balls  m  and  m' 
are  placed  upon  the  hand  rope.  These  balls  are  made  of  such  a  size 
that  they  cannot  pass  through  the  openings  in  the  floor  and  roof  of  the 
car  through  which  the  rope  passes ;  therefore,  when  the  car,  running 
upward,  strikes  the  upper  ball  m,  the  latter  goes  up  with  the  car  and 
pulls  upward  the  hand  rope,  thereby  moving  the  control  valve  back  to 
the  stop  position.  Should  the  car  fail  to  stop,  the  valve  would  be 
carried  beyond  the  stop  position  and  would  connect  both  ends  of  the 
cylinder  so  as  to  cause  the  car  to  run  down.  This  reversal  of  the  motion 
of  the  car  cannot  occur  when  everything  is  in  proper  adjustment,  for 
under  such  conditions,  when  the  valve  is  completely  closed,  the  car  will 
stop.  If,  however,  the  car  should  run  away  by  any  mishap,  it  might 
run  beyond  the  normal  limit  of  travel,  and  then  the  valve  would  be 
slightly  opened  in  the  opposite  direction,  just  enough  to  develop  a  retard- 
ing force  sufficient  to  stop  the  car.  The  action  when  the  car  approaches 
the  bottom  floor  is  the  same  as  when  it  approaches  the  top;  that  is,  the 
lower  stop  ball  m'  is  struck  and  carried  down  with  the  car,  thereby 
closing  the  operating  valve.  The  balls  m  m'  are  known  as  automatic 
top  and  bottom  limit  stops,  and  constitute  one  of  the  most  valuable 
safety  devices  with  which  elevators  are  provided,  although  this  fact  is 
not  generally  realized  as  fully  as  it  should  be.  Most  men  appear  to 
regard  them  as  convenient  devices  used  to  stop  the  car  if  the  operator 
fails  to  do  so,  and  to  think  that  if  they  were  not  used,  the  car  would 


36  HYDRAULIC  ELEVATORS 

simply  strike  the  bumpers  a  rather  hard  blow.  This  would  be  the  case 
with  very  slow  running  cars,  but  at  high  speeds,  if  the  automatic  limit 
stops  were  not  used,  serious  results  would  be  produced  if  the  operator 
neglected  to  stop  the  car  in  time. 

It  can  be  readily  seen  that  if  the  capacity  of  the  lifting  cylinder  is 
sufficient,  the  car  can  be  run  at  a  much  higher  speed  than  is  desirable 
if  the  valve  is  opened  to  its  full  capacity.  To  obviate  this  difficulty, 
stops  are  provided  so  that  the  operator  when  pulling  on  the  hand  rope 


FIG.  26 

cannot  open  the  valve  beyond  the  amount  necessary  to  give  the  maximum 
car  speed.  These  stops,  which  are  usually  mounted  at  some  convenient 
point  in  the  elevator  well,  are  set  above  and  below  the  stop  balls  m  m' , 
so  as  to  limit  the.  distance  through  which  the  latter  can  be  moved.  In 
some  cases  additional  stop  balls  are  used,  on  account  of  its  not  being 
convenient  to  place  stops  to  act  directly  upon  m  and  m'.  The  positions 
of  these  stops  that  limit  the  amount  of  opening  of  the  valve  are  deter- 
mined experimentally  when  the  elevator  is  installed. 


VERTICAL  HYDRAULIC  ELEVATORS 


37 


To  keep  the  car  from  striking  the  sides  of  the  elevator  well  it  is  run 
between  guides,  shown  at  M  M  in  Fig.  25.  In  the  construction  here 
illustrated  the  guides  are  made  of  hard  wood.  The  car  is  guided  at  the 
top  by  shoes  that  fit  freely  against  the  guides  and  are  provided  with 
means  for  adjusting  them  so  as  to  be  neither  too  tight  nor  too  loose. 
At  the  bottom  the  car  is  guided  by  jaws  formed  in  a  safety  device  that 
was  formerly  known  as  a  safety  plank,  but  at  the  present  time  is 
generally  spoken  of  simply  as  a  "safety."  It  received  the  name  of 
"safety  plank"  from  the  fact  that  it  is  made  of  a  massive  hard-wood 
plank,  varying  from  4  inches  thick  and  n  inches  wide  in  the  smaller 


N 


FIG.   27 

sizes,  to  5  inches  thick  and  15  inches  wide  in  the  larger  ones.  The 
jaws  of  this  safety  are  reinforced  with  massive  iron  castings,  and  on 
one  side  are  provided  with  a  wedge  that  can  be  adjusted  in  position  by 
means  of  screws,  and  on  the  opposite  side  with  another  wedge  that  can 
be  forced  between  the  guide  and  the  jaw  to  stop  the  car  if  one  of  the 
lifting  ropes  breaks,  or  the  car  attains  an  excessive  velocity  from  any 
cause.  This  safety  is  not  very  clearly  shown  in  Fig.  25.  By  the  aid  of 
Fig.  26,  and  the  drawing  Fig.  27,  which  shows  one  end  of  the  safety 
plank,  its  construction  and  operation  can  be  fully  understood.  In  the 
latter  figure  the  governor  rope  rod  L  is  shown  only  in  the  end  elevation. 
Looking  at  Fig.  26  it  will  be  seen  that  the  two  lifting  ropes  that  run 


38  HYDRAULIC  ELEVATORS 

down  to  either  side  of  the  car  are  connected  with  the  ends  of  a  rocking 
lever  C.  This  lever  C,  as  shown  in  Fig.  27,  is  pivoted  at  D' ',  hence  if 
either  one  of  the  lifting  ropes  breaks,  the  end  of  the  lever  it  is  attached 
to  will  drop  down.  The  shaft  PI,  which  runs  under  the  car  from  one 
side  to  the  other,  carries  at  its  end  a  lever  L'  that  when  raised  lifts  the 
wedge  N  and  forces  it  into  the  space  between  the  guide  M  and  the  side 
of  the  jaw  of  the  safety  plank.  Whichever  way  the  lever  C  may  be 
tilted  by  the  breaking  of  one  of  the  lifting  ropes,  it  will  rotate  the  shaft 
H  and  lever  L'  in  the  proper  direction  to  throw  up  the  wedges  N  and 
thereby  lock  the  car  against  the  stationary  guides  M.  The  levers  on  the 
end  of  the  shaft  H  are  long  enough  to  strike  the  guides  M,  when  raised 
high  enough,  and  are  sharp  at  the  ends  so  that  they  will  cut  into  the 
guides. 

It  might  be  thought  that  if  the  wedge  N  is  only  raised  far  enough 
to  catch  in  the  space  between  the  guide  M  and  the  safety-plank  jaw  it 
would  be  forced  upward  so  tightly  as  to  stop  the  car  without  further 
assistance.  This  would  be  the  case  if  the  wedge  had  a  sufficiently  long 
taper,  but  if  it  were  so  proportioned,  it  would  require  an  enormously 
strong  jaw  to  resist  the  bursting  strain;  moreover,  the  car  would  be  so 
tightly  wedged  that  it  would  require  a  greater  force  to  release  it  than 
could  be  easily  obtained.  With  the  wedges  of  the  proportions  used,  it  is 
necessary  to  make  the  lever  that  lifts  the  wedge  so  that  it  will  dig  into 
the  guide,  and  as  the  car  moves  down  through,  say,  a  foot  or  two  in 
coming  to  a  stop,  the  lever  shaves  the  side  of  the  guide,  thereby  not 
only  forcing  the  wedge  tighter  against  the  guide,  but  producing  an 
additional  retarding  force.  When  a  car  is  caught  by  the  safety,  all  that 
is  necessary  to  release  it  is  to  start  in  the  upward  direction,  and  the 
force  exerted  by  the  lifting  cylinder  is  enough  to  overcome  the  friction 
of  the  wedges  against  the  guides. 

In  the  foregoing  wre  have  shown  how  this  safety  acts  providing  one 
of  the  ropes  breaks.  Elevator  cars,  however,  seldom  drop  when  one  of  the 
ropes  breaks,  but  frequently  attain  very  high  velocity  when  the  ropes 
do  not  break,  and  on  that  account  it  is  necessary  that  the  safety  be 
arranged  so  as  to  act  when  the  speed  reaches  a  certain  point,  no  matter 
what  causes  the  increased  velocity.  This  result  is  accomplished  in  the 
safety  shown  in  Fig.  25  by  means  of  the  Otis  safety  governor  seen 
mounted  on  one  of  the  overhead  beams.  This  governor  is  driven  by 
the  rope  L  which  is  fastened  to  one  end  of  the  lever  G' ',  as  clearly  shown 
at  G,  Fig.  26.  The  spring  that  holds  Gr  is  strong  enough  to  keep  the 
lever  in  the  normal  position  and  rotate  the  safety  governor;  hence,  the 
latter  will  rotate  at  a  velocity  proportional  to  the  speed  of  the  car.  A 
drawing  of  the  governor  is  shown  in  Fig.  28,  and  it  will  be  seen  from 


VERTICAL  HYDRAULIC  ELEVATORS 


39 


this  that  the  governor  can  be  adjusted  by  means  of  the  spring  on  the 
spindle  to  act  at  any  desired  velocity.  The  governor  driving  rope  passes 
through  the  clamping  jaws  H  H' ,  and  when  the  governor  speed  becomes 
great  enough  to  lift  the  rod  Z  and  throw  the  jaws  together,  the  rope 
will  be  clamped.  Then,  as  the  rope  cannot  move,  the  outer  end  of  the 
lever  G'  on  the  safety  plank  will  be  held  stationary  as  the  car  descends; 
hence,  the  shaft  H  will  be  rotated,  throwing  the  safety  wedges  N  into 
action  to  stop  the  car. 

It  is  evident  that  the  car  can  descend  only  as  far  as  the  upward 
movement  of  the  end  of  the  lever  G'  and  the  compression  of  the  spring 
on  L  will  permit  before  the  rope  will  have  to  slide  through  the  clamps 


FIG.  28 

H  H'  of  the  governor.  Now  as  the  distance  through  which  the  spring 
can  be  compressed,  plus  the  movement  of  the  end  of  G',  is  only  a  few 
inches,  it  follows  that  unless  the  car  is  stopped  very  short,  the  rope  L 
must  break  if  it  cannot  slide  through  the  clamps  H  H'.  The  distance 
in  which  the  car  will  stop  is  always  considerably  more  than  the  com- 
pression of  the  spring  plus  the  movement  of  the  end  of  G' ;  hence,  while 
it  is  necessary  for  H  H'  to  clamp  the  rope  tight  enough  to  move  G',  the 
pressure  must  not  be  so  great  as  to  prevent  the  rope  from  slipping.  For 
the  same  reason,  in  order  to  make  the  safety  governor  reliable  it  is 
necessary  that  the  operating  rope  shall  be  in  just  as  good  condition  as 
the  elevator  lifting  ropes.  The  failure  to  inspect  this  rope  properly  and 


40  HYDRAULIC  ELEVATORS 

make  sure  that  it  is  at  all  times  in  perfect  condition  has  been  a  prolific 
cause  of  accidents. 

The  jaws  of  the  safety  plank  and  the  wedge  N  should  be  kept  clean 
and  in  proper  adjustment  at  all  times.  As  the  guides  M  have  to  be 
kept  well  lubricated,  it  can  be  easily  seen  that  if  the  safety  jaws  are 
neglected  they  will  soon  become  clogged  with  a  mixture  of  grease  and 
dust,  and  this  may  give  considerable  trouble  by  causing  the  wedge  to 
stick  to  the  side  of  the  guide  and  thus  go  into  action  when  everything 
else  is  running  in  proper  condition.  The  wedge  N  and  the  adjusting 
wedge  on  the  opposite  side  of  the  guide  will  wear  away  gradually ;  there- 
fore, the  latter  must  be  set  up  as  often  as  required  to  keep  the  clearance 
between  the  guide  and  the  safety  jaw  of  the  proper  amount.  If  the 
clearance  is  too  great  the  wedge  N  is  liable  to  not  catch  firmly  when 
called  into  action,  and  if  the  clearance  is  too  small,  the  safety  is  liable 
to  act  without  cause. 

The  operating  valve  shown  in  Fig.  25  is  the  same  in  general  principle 
as  the  one  shown  diagrammatically  in  Fig.  7,  but  has  several  details  of 
construction  that  are  not  illustrated  in  the  latter.  Its  actual  design  can 
be  readily  understood  from  Fig.  29,  which  is  a  sectional  elevation  of  the 
valve  and  the  casing.  The  casing  is  made  in  three  parts,  marked  7,  8  and 
p.  The  first  forms  the  top,  and  provides  a  dome  into  which  the  rack  6 
on  the  end  of  the  valve  rod  can  rise  as  the  valve  is  lifted  by  the  rotation 
of  the  pinion  on  the  end  of  the  shaft  A.  This  shaft  carries  at  its  outer 
end  the  hand-rope  sheave  shown  at  the  side  of  the  valve  in  Fig.  25.  The 
parts  7  and  8  are  divided  at  the  center  of  the  shaft  A  and  form  a 
bearing  for  the  latter.  The  lower  part  p,  which  is  the  valve  casing 
proper,  has  ports  10  and  n  for  connection  with  the  lower  end  of  the 
circulating  pipe  and  the  lower  end  of  the  cylinder  in  the  manner  indi- 
cated by  Fig.  7. .  The  part  into  which  the  circulating  pipe  is  connected 
forms  a  separate  casting  in  Fig.  25,  and  the  casing  p  is  bolted  to  it.  The 
port  12  in  part  p  of  the  valve  casing  is  for  the  purpose  of  connecting 
with  the  pressure-water  supply  if  for  any  reason  it  is  not  desired  to 
have  this  connection  made  in  the  circulating  pipe.  The  valve  casing  is 
lined  with  brass  tubing  4  and  j.  The  former  is  simply  for  the  purpose 
of  providing  a  smooth  surface  for  the  cup  packing  of  V  to  slide  against, 
but  the  latter  is  provided  for  the  additional  purpose  of  making  ports  of 
such  a  character  that  the  cup  packings  of  V  may  be  able  to  slide  over 
them  readily.  If  the  ports  were  large  openings,  the  packings  could  not 
pass  over  them  because  on  the  up  movement  they  would  be  caught  by 
the  edges  of  the  ports.  With  the  brass  linings  this  trouble  is  overcome 
by  perforating  the  brass  with  a  large  number  of  small  holes,  about  one- 
quarter  of  an  inch  in  diameter.  The  combined  area  of  the  holes  is 


VERTICAL  HYDRAULIC  ELEVATORS 


much  larger  than  would  be  required  in  a  single  port,  this  increase  in 
opening  being  provided  so  as  to  reduce  the  friction  of  the  water  running 
through  the  holes  by  reducing  the  velocity  of  flow. 

The  pressure  of  the  water  tends  to  force  the  valve  piston  V  upward, 
and  the  other  piston  V  downward ;  both  pistons  being  of  the  same 
diameter,  the  valve  is  balanced.  The  force  necessary  to  move  the  valve 


FIG.  29  FIG.  30 

is  considerable,  however,  as  the  friction  of  the  cup  packings  is  great, 
being  produced  by  the  pressure  of  the  water  acting  upon  the  entire 
surface  of  the  leather  in  contact  with  the  brass  linings  of  the  valve 
casing.  On  this  account  the  pinion  on  the  shaft  A,  through  which  the 
valve  is  moved,  is  made  very  small,  while  the  hand-rope  sheave  is  large 
— about  20  inches  in  diameter — so  that  while  the  valve  travels  a  few 
inches  in  either  direction  the  hand  rope  has  to  be  pulled  through  a 
distance  of  from  two  to  four  feet,  according  to  the  size  of  the  valve  and 
the  speed  of  car.  For  high  car  speeds  the  hand  rope  movement  is 
increased,  so  that  the  automatic  top  and  bottom  stops  may  be  able  to 
arrest  the  movement  of  the  car  without  making  the  stop  abruptly. 


42  HYDRAULIC  ELEVATORS 

In  looking  at  the  lower  end  of  valve  piston  V  it  will  be  noticed  that 
the  lower  head  that  clamps  the  packing  2  is  made  tapering;  this  is  done 
so  that  in  moving  the  valve  down,  to  stop  the  car  on  the  up  trip,  the 
outlet  from  the  lower  end  of  the  cylinder  may  not  be  closed  so  quickly 
as  to  produce  a  violent  stop.  Even  with  this  precaution  it  is  possible  for 
the  operator  to  close  the  valve  too  rapidly;  hence,  in  addition  to  this 
tapering  of  the  main  valve,  a  check  valve  is  inserted  in  the  passage  that 
connects  the  valve  casing  with  the  cylinder.  This  check  is  directly 
under  the  lower  end  of  the  circulating  pipe,  so  that  if  the  operator  closes 
the  valve  too  suddenly  the  descent  of  the  piston  in  the  cylinder  will  not 
be  arrested  instantly,  but  will  continue  its  movement,  and  force  the 
water  under  it  to  pass  through  the  relief  check  valve  into  the  circulating 
pipe  and  thus  to  the  upper  end  of  the  cylinder. 

If  the  operator  moves  the  hand  rope  so  quickly  on  the  down  trip  as 
to  produce  a  violent  stop,  the  piston  will  continue  to  rise  in  the  cylinder 
and  the  water  above  it,  which  cannot  pass  to  the  lower  end  of  the 
cylinder  on  account  of  the  valve  being  closed,  will  be  forced  back 
through  the  inlet  pipe  /  to  the  pressure  tank.  In  this  case,  as  no  water 
can  pass  into  the  lower  end  of  the  cylinder,  the  continued  upward 
movement  of  the  piston  causes  it  to  leave  the  water  and  thus  form  a 
vacuum.  This  vacuum,  combined  with  the  pressure  in  the  tank,  soon 
arrests  the  movement  of  the  car — in  fact,  in  a  very  few  inches — but  the 
stop  is  not  so  sudden  as  to  jolt  the  passengers,  as  would  be  the  case  if 
there  were  no  relief  for  the  water  imprisoned  in  the  cylinder. 

One  objection  to  having  the  connection  between  the  cylinder  and  the 
pressure  tank  through  the  inlet  pipe  7  is  that  if  for  any  reason  the 
pressure  in  the  tank  should  drop,  as  by  the  springing  of  a  bad  leak,  the 
water  in  the  upper  end  of  the  cylinder  can  immediately  run  out,  and 
with  such  freedom  that  if  the  car  were  at  the  top  of  the  building,  as  in 
Fig.  25,  it  would  attain  a  dangerous  speed  by  the  time  it  reached  the 
bottom.  This  danger  can  be  entirely  obviated,  however,  by  placing  the 
pressure  tank  on  the  roof,  so  that  the  water  in  the  cylinder  has  to  run 
out  against  a  head,  due  to  the  elevation  of  the  tank.  To  this  head  is 
added  the  pressure  of  the  atmosphere,  because  as  the  valve  is  closed  no 
water  can  pass  into  the  lower  end  of  the  cylinder,  and  as  the  piston  runs 
up  a  vacuum  is  formed  under  it,  and  these  combined  pressures  are 
sufficient  to  prevent  the  car  from  attaining  a  dangerously  high  speed  in 
its  descent. 

When  the  pressure  tank  is  placed  in  the  basement  the  danger  above 
referred  to  is  avoided  by  using  a  valve  of  the  type  shown  in  Fig.  30. 
The  difference  between  this  valve  and  that  of  Fig.  29  is  that  it  is  provided 
with  an  additional  piston  V" ,  which  is  called  the  throttle  valve.  When 


VERTICAL  HYDRAULIC  ELEVATORS 


43 


this  valve  is  used,  the  inlet  pipe  from  the  pressure  tank  is  attached  to 
the  port  12.  When  the  elevator  is  stopped,  the  throttle  valve  V"  is 
directly  opposite  the  port  12,  and  thus  obstructs  the  flow  of  water  from 
the  port  JO.  It  will  be  seen  that  a  groove  is  turned  in  V"  at  the  center 
line ;  in  addition  the  valve  is  not  made  a  perfect  fit  in  the  valve  casing, 
and  the  clearance  afforded  by  these  two  features  is  sufficient  to  permit 
water  to  pass  by  in  as  large  an  amount  as  may  be  necessary  to  prevent 
too  sudden  a  stoppage  of  the  car,  if  the  operator  should  close  the  valve 


FIG.  31 

too  quickly ;  but  it  will  not  allow  the  water  to  flow  through  fast  enough 
to  enable  the  car  to  descend  at  a  high  velocity  if  the  pressure  in  the 
tank  should  fail. 

When  the  valve  is  moved  in  either  direction  to  set  the  car  in  motion 
the  water  passes  from  the  port  12  to  the  port  10,  there  being  sufficient 
opening  around  the  throttle  valve,  even  when  the  operating  valve  piston 
V  is  only  slightly  open. 

The  pistons  used  in  vertical  hydraulic  elevators  are  made  in  several 
designs,  some  being  arranged  so  as  to  be  packed  from  the  upper  end, 
and  others  so  as  to  be  packed  from  the  lower  end.  Fig.  31  shows  one 


44  HYDRAULIC  ELEVATORS 

of  the  latest  designs  of  pistons  arranged  to  be  packed  from  the  lower 
end  of-  the  cylinder,  which  appears  to  be  the  favorite  type  now.  The 
drawing  shows  a  section  through  the  complete  piston,  with  packing  in 
place,  also  a  section  of  the  cylinder  C.  Ordinary  square  packing  is  used, 
and  this  is  held  in  position  by  a  follower  secured  by  six  bolts.  The 
parts  P  and  P"  are  made  to  fit  the  cylinder,  but  the  intervening  section 
is  cut  away  on  opposite  sides,  so  as  to  afford  space  for  the  ends  of  the 
piston-rods  and  their  fastening  nuts.  The  top  and  bottom  parts  of  the 
piston  are  connected  by  the  pillars  i  and  /. 

In  packing  these  pistons  it  is  necessary  to  be  careful  not  to  press  the 
packing  in  too  tight,  as  there  is  danger  of  bursting  the  cylinder  by  so 
doing,  and  even  if  this  much  damage  is  not  done  the  friction  caused  by 
the  excessive  pressure  may  be  so  great  as  to  prevent  the  car  from 
attaining  its  full  velocity.  If  a  hard  packing  is  used,  and  this  is  forced 
into  place  dry  and  very  tight,  the  chances  are  that  when  it  becomes  well 
soaked  it  will  expand  enough  to  burst  the  cylinder.  Bursting  hydraulic- 
elevator  cylinders  is  not  a  very  rare  occurrence,  and  when  it  does  occur 
it  is  due  to  too  great  pressure  of  the  piston  packing  against  the  sides  of 
the  cvlinder. 


CHAPTER  VIII 

LOW-PRESSURE  VERTICAL  TYPE  ELEVATOR  LEVER 

CONTROL 

In  Chapter  VII  we  discussed  the  vertical-cylinder  elevator  of  the 
type  used  in  buildings  from  five  to  seven  or  eight  stones  high.  The 
same  style  of  elevator  could  be  used  for  higher  runs,  by  increasing  the 
gear  to  three  or  four  to  one,  but  it  is  not  desirable  to  do  so,  owing  to 
the  fact  that  as  the  hight  of  the  building  increases  the  car  speed  is 
increased,  and  hand-rope  control  is  not  satisfactory  when  the  car  runs 
faster  than  about  250  feet  per  minute.  When  a  car  runs  at  a  low 
velocity  the  operator  can  control  it  perfectly  by  means  of  the  hand  rope ; 
but  as  the  velocity  increases,  the  difficulty  of  making  accurate  stops  at 
the  floors  of  the  building  becomes  so  great  that  only  the  most  experienced 
elevator  operators  can  control  the  movement  of  the  car  in  a  manner  to 
give  satisfaction  to  the  passengers.  Furthermore,  the  difficulty  of  con- 
trolling a  high-speed  car  by  means  of  a  hand  rope  is  due  not  only  to 
the  increased  velocity,  but  also  to  the  fact  that  more  effort  is  required 
to  move  the  valve,  as  the  latter  must  be  increased  in  size,  owing  to  the 
fact  that  more  power  is  required  to  develop  the  higher  speed.  The 
effort  to  move  the  hand  rope  can  be  kept  down  somewhat  by  increasing 
the  distance  through  which  it  must  be  moved  to  open  or  close  the  valve, 
but  this  does  not  help  matters  very  much. 

Even  if  the  difficulty  of  car  control  could  be  entirely  overcome,  the 
hand  rope  would  still  be  objectionable  for  high  speeds,  because  it  would 
be  necessary  to  adjust  the  automatic  top  and  bottom  stops  so  as  to  retard 
the  car  too  rapidly  to  make  a  satisfactory  stop  or  else  give  the  hand 
rope  so  much  movement  that  the  operator  could  not  make  at  intermediate 
floors  as  quick  stops  as  are  often  required.  For  these  reasons  the  hand- 
rope  control  is  not  used  in  high-speed  elevators  intended  for  first-class 
service. 

In  place  of  the  hand  rope  an  operating  lever  is  used,  and  as  the 
movement  of  the  end  of  this  is  only  through  a  distance  of  about  one 
foot,  it  would  be  next  to  impossible  for  the  operator  to  move  the 
operating  valve  by  it  if  a  direct  connection  were  made,  for  it  would 
require  an  effort  that  even  an  athlete  could  not  exert  for  more  than  a 
few  minutes.  To  get  around  this  difficulty,  a  small  valve  operated  by 
the  car  lever  is  provided,  and  this  valve  controls  the  flow  of  water  in 
and  out  of  a  motor  cylinder,  the  piston  of  which  moves  the  main 

45 


46 


HYDRAULIC  ELEVATORS 


operating  valve.  This  small  valve  is  called  a  "pilot,"  and  elevators  in 
which  it  is  used  are  said  to  be  provided  with  "a  pilot-valve  and  car-lever 
control."  An  elevator  of  this  type,  as  made  by  the  Otis  Elevator  Com- 
pany, geared  four  to  one,  is  shown  in  Fig.  32. 

It  will  be  noticed  in  this  illustration  that  there  is  an  extension  at  the 
top  of  the  valve  chamber,  on  the  right  side.  This  extension  carries  the 
pilot  valve  and  also  a  sheave  /.  This  sheave  moves  the  pilot  valve,  and 


FIG.  32 
OTIS  VERTICAL  HYDRAULIC  ELEVATOR  FOR  FIRST-CLASS  PASSENGER  SERVICE 

the  movement  of  the  latter  controls  the  flow  of  water  into  and  out  of 
the  upper  end  of  the  main  valve  chamber,  which,  as  will  be  seen,  is  of 
larger  diameter  than  the  lower  portion.  In  this  enlarged  end  of  the 
valve  chamber  is  located  a  piston  that  moves  the  main  valve.  The 
sheave  /  is  rotated  through  a  small  angle,  in  either  direction,  by  sheave 
2;  the  latter  carries  on  one  side  two  smaller  sheaves  over  which  pass 
ropes  n  that  run  up  the  elevator  well  and  at  the  top  of  the  building 
pass  over  two  similar  sheaves  which  are  stationary.  These  ropes  are 


LOW-PRESSURE  VERTICAL  TYPE  ELEVATOR  LEVER  CONTROL      47 

connected  with  a  lever  mounted  on  the  rear  end  of  a  shaft  running 
under  the  elevator  car,  and  which  carries  at  its  front  end  a  lever  that 
projects  up  through  the  floor  of  the  car.  This  is  the  operating  lever, 
and  by  turning  it  in  one  direction  the  sheave  I  is  caused  to  rotate  in  a 
corresponding  direction,  say  in  the  direction  that  will  move  the  pilot 
valve  so  as  to  cause  the  car  to  ascend.  Moving  the  car  lever  in  the 
opposite  direction  will  cause  the  car  to  descend. 

The  pressure  water  enters  through  pipe  A  and  is  discharged  through 
pipe  D,  in  the  lower  end  of  the  cylinder.  At  B'  is  placed  a  speed- 
regulating  valve,  the  office  of  which  is  to  prevent  the  car  from  running 
at  too  high  a  velocity  if  the  operator  throws  the  main  valve  wide  open 
when  the  load  is  light.  At  B",  between  the  main  valve  and  the  lower 
end  of  the  cylinder,  is  located  a  valve  which  stops  the  car  automatically 
at  the  top  and  bottom  floors  of  the  building.  This  valve  is  actuated  by 
the  rope  5,  which  passes  through  the  end  of  arm  /  projecting  from  one 
side  of  the  traveling-sheave  frame.  The  rope  passes  over  a  sheave  6 
and  thence  runs  down  and  around  a  sheave  mounted  on  the  back  end 
of  a  shaft  carrying  a  pinion  which  meshes  into  the  gear  on  the  automatic 
stop  valve  B" . 

The  illustration  shows  a  car  running  on  iron  guides,  which  are  the 
only  kind  permitted  in  fireproof  buildings.  For  metal  guides  the  wedge 
safety  shown  in  Fig.  25  cannot  be  used,  as  the  friction  of  wood  against 
iron  is  too  uncertain,  being  considerable  if  there  is  any  grit  between 
the  surfaces,  and  slight  if  there  is  no  grit  and  the  surfaces  are  well 
lubricated.  The  safety  shown  in  Fig.  32  is  of  the  type  known  as  a 
clamp,  or  brake  safety.  It  is  also  called  a  drum  safety,  or  a  toggle-joint 
safety.  It  is  given  all  these  names  because  it  is  a  brake  made  in  the 
form  of  heavy  shoes  that  are  clamped  tightly  against  the  elevator  guides 
by  means  of  the  toggle  joint,  or  equivalent  devices,  operated  by  the 
rotation  of  a  drum  placed  in  the  safety  at  a  point  between  the  two  ends. 

The  construction  and  operation  of  the  several  parts  of  Fig.  32  can 
be  better  explained  in  connection  with  the  line  drawing  Fig.  33,  and  in 
other  line  drawings  which  follow.  In  Fig.  33  the  speed-regulating  valve 
B'  is  not  shown,  and  the  rope  connections  for  transmitting  the  motion 
of  the  car  lever  to  the  pilot-valve  sheave  I  are  not  the  same.  There  are 
many  modifications  of  these  rope  connections,  but  all  of  them  are 
classified  under  two  generic  systems  known  as  the  "running  rope"  and 
"standing  rope."  The  arrangement  of  Fig.  32  is  of  the  running-rope 
type,  while  that  of  Fig.  33  is  of  the  standing-rope. 

THE   STANDING-ROPE   SYSTEM. 

The  operation  of  the  standing-rope  system  can  be  more  easily  under- 
stood from  Fig.  34,  which  shows  the  rope  connections  complete  and 


FIG.  33 
OTIS    VERTICAL    HYDRAULIC    ELEVATOR 


LOW-PRESSURE  VERTICAL  TYPE  ELEVATOR  LEVER  CONTROL       49 

free  from  other  complications.  The  rope  n'  comes  down  from  top 
sheave  J  on  the  right,  and  passes  under  the  right-side  sheave  carried  by 
the  cross  lever  connected  with  the  car-operating  lever.  From  the  under 
side  of  the  right-side  sheave  the  rope  passes  to  and  around  the  top  of 


Operating  Sh«M» 
on  Valve  i 


FIG.  34 
ILLUSTRATING    OPERATION    OF    STANDING-ROPE    SYSTEM 

the  left  sheave,  and  thence  down  and  under  the  two  lower  stationary 
sheaves  2,  2,  then  up  and  around  the  pilot-valve  operating  sheave,  and 
under  the  two  central  stationary  sheaves  2,  2,  thence  over  the  right  and 
under  the  left  sheaves  carried  by  the  car  lever,  and  so  on  up  over  top 
sheave  j,  where  the  two  ends  of  the  rope  are  connected  and  from  their 
end  is  suspended  the  tension  weight  j'.  If  the  car  lever  is  moved  to  the 
right,  the  ropes  n  will  slacken  up  while  the  ropes  n'  will  draw  up,  from 
the  fact  that  the  right-side  sheave  will  be  depressed  and  the  left-side  one 
elevated.  This  change  in  the  ropes  will  rotate  the  pilot-valve  sheave 
clockwise.  If  the  car  lever  is  moved  to  the  left,  the  action  will  be  just 
the  opposite  and  the  valve-operating  sheave  will  be  rotated  counter- 
clockwise. Thus,  through  the  taking  up  of  one  rope  and  the  letting  out 
of  the  other,  the  pilot-valve  operating  sheave  is  made  to  move  in  accord 


50  HYDRAULIC  ELEVATORS 

with  the  movement  of  the  car  lever.  This  system,  which  as  already 
explained  is  made  in  several  modified  forms,  is  called  the  standing  rope, 
because  the  ropes  remain  stationary  while  the  car  is  running.  In  running- 
rope  systems,  the  ends  of  the  ropes  are  fastened  to  the  car  lever,  or 
two  ends  to  the  lever  and  two  to  the  car,  and  the  ropes  run  when  the 
car  runs. 

Returning  to  Fig.  33,  it  will  be  seen  that  when  the  sheave  i  is  rotated 
clockwise,  the  lever  4  is  pulled  down  by  the  connecting-rod  /j,  the  lower 
end  of  which  is  connected  with  the  crank  on  the  sheave  shaft.  This 
downward  movement  of  4  will  depress  rod  14,  and  thus  move  downward 
the  pilot  valve  V2,  simply  because  it  is  easier  to  move  this  end  down 
than  the  opposite  end  which  is  connected  with  the  top  of  the  main  valve- 
rod.  When  the  pilot  valve  is  moved  down,  pressure  v^ater  will  flow 
from  pipe  A  through  the  small  pipe  A'  to  and  through  the  valve  to  pipe 
A" ',  and  thus  to  the  upper  end  of  the  main  valve  chamber,  above  the 
motor  piston  V '. 

The  pressure  water  is  at  all  times  in  the  space  between  valve  V  and 
the  under  side  of  V  and  also  in  the  space  above  V ,  but  so  long  as 
water  cannot  pass  in  or  out  of  this  latter  space  the  main  valve  cannot 
move,  for  it  could  not  move  upward  without  compressing  this  water, 
and  it  could  not  move  downward  without  forming  a  vacuum  above  V. 
As  there  is  pressure  water  above  and  below  V,  this  valve  taken  by  itself 
is  in  a  state  of  perfect  balance,  but  the  main  valve  V  is  unbalanced, 
because  the  pressure  water  acts  against  its  upper  side,  while  only  the 
pressure  of  the  discharge  tank  acts  against  its  lower  side.  As  a  result 
of  this  state  of  things,  as  soon  as  water  enters  the  space  above  V ,  this 
piston  will  move  down,  carrying  the  main  valve  with  it,  thus  connecting 
the  top  and  bottom  of  the  cylinder,  so  that  the  water  may  circulate  and 
the  piston  run  upward.  It  will  be  noticed  that  as  soon  as  V  begins  to 
move  down  by  the  admission  of  water  above  it,  the  pilot  valve  is  moved 
upward,  because  rod  13  will  be  held  stationary  by  sheave  I.  When  V 
moves  down  a  certain  distance,  it  will  have  moved  the  pilot  valve  upward 
to  the  central  or  stop  position;  that  is,  the  position  in  which  the  flow 
of  water  into  the  space  above  V  is  stopped;  hence,  when  this  point  is 
reached  V  will  descend  no  farther. 

If  the  sheave  i  is  turned  counter-clockwise,  rod  14  will  be  lifted  and 
thus  pull  up  the  pilot  valve  Vz,  and  this  movement  will  connect  pipe  A" 
with  pipe  16  and  permit  the  water  in  the  space  above  V  to  run  out  into 
the  discharge  pipe  D,  and  the  main  valve  to  ascend  and  connect  the 
lower  end  of  the  cylinder  with  the  discharge  pipe;  so  that  the  piston 
may  run  down  and  pull  up  the  elevator  car.  In  this  movement  it  will 
again  be  seen  that  as  soon  as  V  begins  to  move  upward,  it  will  move 


LOW-PRESSURE  VERTICAL  TYPE  ELEVATOR  LEVER  CONTROL       51 

rod  14  downward,  and  thus  depress  the  pilot  valve  until  it  reaches  the 
stop  position  and  closes  off  the  connection  between  A"  and  the  pipe  16. 
To  fully  understand  this  movement  of  V  it  must  be  remembered  that 
the  pressure  in  pipe  16  is  much  below  that  in  the  pipe  A,  so  that  when 
A"  is  connected  with  16  the  pressure  above  V  is  greatly  reduced,  and 
the  latter  being  unbalanced  will  be  forced  upward  by  the  pressure  under 
it,  which  will  be  greater  than  the  downward  pressure  on  V,  owing  to 
the  difference  in  the  diameters  of  the  two  pistons. 

The  distance  through  which  the  sheave  /  is  rotated  depends  upon 
the  distance  through  which  the  car-operating  lever  is  moved,  so  that  if 
the  latter  is  moved  a  short  distance  the  sheave  i  will  rotate  through  a 
small  angle.  In  this  case  the  pilot  valve  will  be  shifted  but  a  short 
distance  from  the  central  position,  and,  therefore,  the  main  valve  will 
only  have  to  move  a  small  portion  of  its  full  stroke  to  return  the  pilot 
to  the  central  position.  If  the  car  lever  is  moved  as  far  as  it  will  go, 
the  rotation  of  the  sheave  /  will  be  through  a  wide  angle,  and  the  pilot 
will  be  shifted  a  considerable  distance  from  the  central  position.  In  this 
case  the  main  valve  will  have  to  move  its  full  stroke  to  return  the  pilot 
to  the  central  position.  Thus  it  will  be  seen  that  in  every  case  the 
opening  of  the  main  valve  is  directly  proportional  to  the  distance  through 
which  the  car  lever  is  moved,  and  the  control  the  operator  in  the  car 
has  over  the  movement  of  the  main  valve  is  as  complete  as  it  would 
be  if  he  stood  by  the  side  of  the  valve  and  effected  its  movement  by 
means  of  a  lever  attached  directly  to  the  piston-rod  15. 


CHAPTER  IX 
PILOT- VALVE  CONTROL— REGULATING  VALVES 

All  modern  hydraulic  elevators  intended  for  first-class  passenger 
service  are  provided  with  a  pilot-valve  control,  and  although  the  design 
in  the  various  types  may  differ  considerably,  the  principle  of  operation 
is  the  same  as  that  of  the  valve  here  shown.  This  design,  however,  is  the 
best  one  from  which  to  gain  a  thorough  knowledge  of  the  principles  of 
operation,  because  it  shows  them  up  very  clearly.  The  stop  screw  2?  is  a 
safety  feature  provided  to  prevent  the  operator  from  opening  the  valve 
wide  enough  to  permit  the  car  to  run  away  when  running  up  with  a 
light  load.  When  the  speed  regulator  B',  shown  in  Fig.  32,  is  used,  this 
stop  simply  becomes  an  additional  precaution,  as  B'  alone  is  capable  of 
taking  care  of  the  car  speed,  if  properly  adjusted. 

The  construction  of  the  main  valve  of  Fig.  33  can  be  easily  under- 
stood from  the  drawing  Figs.  35  and  36.  Fig.  35  is  a  vertical  elevation 
in  section,  showing  the  valve  in  the  stop  position.  Fig.  36  is  a  horizontal 
section  taken  on  line  A — B,  just  above  the  port  with  which  the  pressure 
pipe  A,  Fig.  33,  is  connected.  The  lower  portion  of  the  valve  is  the 
same  as  that  shown  in  Fig.  30,  and  so  is  the  corresponding  part  of  the 
valve  chamber. 

The  upper  part  differs  from  the  last-named  valve  simply  in  that  it  is 
of  a  larger  diameter.  In  the  simple  hand-rope  valve  the  pistons  V  and  V 
are  made  of  the  same  diameter,  so  that  the  pressure  of  the  water  pushing 
up  against  V  may  be  just  equal  to  the  pressure  pushing  down  upon  V, 
to  produce  a  perfect  balance  and  make  the  valve  as  easily  movable 
upward  as  downward,  disregarding  the  weight  of  the  valve  itself.  In 
the  valve  here  shown  it  is  necessary  to  make  V  of  a  larger  diameter 
than  Vt  so  that  when  the  pressure  above  V  is  reduced  the  valve  may 
become  unbalanced  and  thus  be  forced  upward  by  the  pressure  acting 
on  the  under  side.  This  valve  is  provided  with  the  throttle  valve  V", 
which  will  prevent  a  runaway  if  for  any  reason  the  pressure  in  the  tank 
drops  to  zero,  or  nearly  so,  and  it  also  prevents  making  a  violent  stop 
on  the  up  trip  if  the  operator  moves  the  lever  to  the  central  or  stop 
position  too  suddenly. 

The  construction  of  the  pilot  valve  is  well  shown  in  Figs.  37  and  38, 
the  first  being  a  sectional  elevation  of  the  valve  and  casing,  showing  the 

52 


PILOT-VALVE   CONTROL — REGULATING    VALVES 


53 


valve  in  the  stop  position,  and  the  second  a  sectional  elevation  of  the 
casing  alone,  taken  at  right  angles  to  Fig.  37.  The  valve  consists  of  a 
sleeve  mounted  upon  the  spindle  Vz,  which  serves  to  hold  in  place  cup 
packings  40,  41  and  42,  as  clearly  shown.  The  pressure  water  enters 
through  the  port  45,  and  passes  to  the  pipe  A"  through  the  port  46.  The 
discharge  water  from  the  upper  end  of  the  main  valve  chamber  enters 
through  the  port  46  and  discharges  through  the  lower  end  47  into  the 
pipe  16  (see  Fig.  33).  The  valve  chamber  is  provided  with  brass  linings, 


Section  A-B 
FIGS.  35-36  FIG.  37  FIG.  38 

and  the  lower  lining  has  numerous  holes  drilled  through  it  opposite  the 
port  46,  so  that  the  cup  packings  may  pass  over  them  on  the  up  stroke 
without  being  caught. 

In  Fig.  37  it  can  be  seen  that  the  packings  only  lap  a  short  distance 
over  the  port  holes  drilled  in  the  brass  lining;  therefore,  the  valve  does 
not  have  to  be  moved  very  far  in  either  direction  to  uncover  the  ports 
and  start  the  elevator.  The  amount  of  lap  of  the  valve  packings  is 
made  sufficient  to  cause  the  valve  to  close  when  the  car  lever  is  some 
distance  from  the  central  position.  If  the  valve  were  made  with  less 
lap,  the  operator  would  have  to  move  the  lever  with  great  accuracy  to 


54 


HYDRAULIC  ELEVATORS 


stop  the  car,  for  if  it  were  not  moved  far  enough  the  car  would  slow 
down  to  a  very  low  speed,  but  would  not  stop;  and  if  the  lever  were 
carried  a  trifle  further  the  car  would  stop  and  then  begin  to  run  in  the 
opposite  direction.  To  obviate  this  trouble  the  valve  packings  are  made 
to  lap  enough  to  require  a  considerable  movement  of  the  car  lever  to 
either  side  of  the  center  to  open  the  ports,  but  not  any  more  than  is 
actually  necessary  for  the  proper  operation  of  the  car. 

In   the  simple  hand-rope   control  elevator  the  car  is   stopped  auto- 
matically at  the  top  and  bottom  landings  by  the  closing  of   the  main 


FIG.  39 

valve  through  the  movement  of  the  hand  rope  by  the  motion  of  the  car 
itself,  the  latter  striking  stop  balls  fastened  to  the  rope  at  the  'proper 
points.  In  the  pilot-valve  control,  as  can  be  seen  in  Fig.  33,  a  separate 
stop  valve  B"  is  placed  between  the  valve  chamber  and  the  lower  end 
of  the  cylinder.  This  valve  is  actuated  by  the  rope  5  which  has  stop 
balls  fastened  to  it  at  proper  points,  as  shown  at  8  and  p.  These  balls 
are  struck  by  the  arm  7  when  the  car  comes  within  proper  distance 
from  either  end  of  its  travel  for  the  automatic  valve  to  start  to  close. 
The  closing  of  this  valve  is  gradual,  so  that  it  does  not  entirely  check 
the  flow  of  water  until  the  car  has  traveled  a  distance  that  may  vary 
from  about  three  feet  up  to  six,  eight  or  more  feet,  depending  upon  the 
speed  at  wrhich  the  elevator  runs.  The  distance  within  which  the  valve 
is  closed  is  determined  by  the  size  of  the  sheave  18,  the  gear  77,  and  a 
pinion  that  drives  77. 


PILOT- VALVE  CONTROL — REGULATING  VALVES 


55 


Looking  at  Fig.  33  it  can  be  seen  that  if  the  car  is  going  up  the  arm  7 
will  descend  and  at  the  proper  time  will  strike  the  stop  ball  p,  and  thus 
carry  the  rope  5  with  it  so  as  to  rotate  the  sheave  18  in  a  clockwise 
direction,  and  the  pinion  of  the  sheave-shaft  will  rotate  //  and  therefore 


FIG.  40 

the  valve  B"  in  a  counter-clockwise  direction,  so  that  the  valve  will  stop 
off  the  flow  of  water  from  under  the  piston  into  the  pipe  D,  by  swinging 
up  and  over  the  port  on  the  right  side  of  the  circular  valve  chamber.  If 
the  car  is  running  up  at  full  speed,  and  is  stopped  entirely  by  the  action 
of  B" ',  it  may  shut  off  the  flow  of  water  faster  than  the  momentum  of 
the  moving  parts  is  overcome  by  the  action  of  gravity,  so  that  the  car 
may  continue  moving  after  the  valve  is  closed.  In  such  a  case  the  car 
ropes  would  tend  to  slack  up,  as  the  piston  could  not  move  any  further, 
owing  to  the  incompressibility  of  the  water.  In  a  case  of  this  kind  there 
would  be  no  such  occurrence  with  the  valve  B"  as  constructed,  because 


56  HYDRAULIC  ELEVATORS 

the  relief  valve  22  would  be  raised,  and  the  water  imprisoned  under  the 
piston  would  find  an  outlet  into  the  lower  end  of  the  circulating  pipe, 
and  thus  to  the  upper  end  of  the  cylinder. 

It  is  very  seldom  that  the  valve  22  is  called  into  action  through  the 
too  sudden  stopping  of  the  car  by  the  action  of  the  valve  B" ' ,  as  this 


FIG.  41 

valve  is  always  adjusted  so  as  to  not  act  so  quickly  as  to  produce  such 
an  effect j  but  sometimes  valves  can  get  out  of  adjustment.  The  principal 
value  of  the  relief  valve  22  is  to  prevent  too  sudden  stops  when  the 
operator  pulls  the  lever  to  the  stop  position  too  rapidly.  This  valve  is 
used  even  with  the  simple  hand-rope  control,  as  was  mentioned  in 
Chapter  VII,  the  casting  which  forms  the  foot  of  the  circulating  pipe 
being  of  the  form  shown  in  Fig.  39,  which  differs  from  the  casting 
shown  in  Fig.  33  only  in  not  having  a  circular  chamber  to  accommodate 
the  valve  B" . 

AUTOMATIC    STOP    VALVE. 

The  construction  of  the  automatic  stop  valve  is  fully  shown  in  Figs. 
40  and  41,  the  first  of  which  is  a  view  taken  at  right  angles  to  the  axis 
of  the  shaft,  with  the  right  side  in  section.  The  other  drawing  is  a 


PILOT- VALVE  CONTROL — REGULATING  VALVES 


57 


view  parallel  with  the  valve-shaft,  and  also  shows  the  right-side  half  in 
section.  The  face  of  the  valve  is  formed  by  the  segment  50,  which  is 
held  in  position  and  moved  by  three-flanged  hubs,  49,  these  latter  being 
firmly  secured  to  the  shaft  53.  The  gear  ij  is  mounted  on  this  shaft, 
and  is  driven  by  the  pinion  55,  which  is  cast  on  one  side  of  the  sheave  18. 
The  segment  50  rotates  within  a  brass  lining  57,  which  has  ports  cut 
through  it  on  both  sides,  the  upper  edge  of  the  ports  being  on  an 
inclined  line,  as  shown  at  52  in  Fig.  41 ;  this  construction  being  for  the 
purpose  of  closing  the  port  gradually  so  as  to  not  stop  the  elevator  too 


FIG.  42 

suddenly.  The  segment  50  is  not  rigidly  secured  to  the  hubs,  49,  for  the 
reason  that,  if  so  made,  it  would  not  be  possible  to  start  the  elevator  from 
either  end  of  the  well. 

This  valve  moves  into  the  position  to  close  the  outlet  from  the  lower 
end  of  the  cylinder,  at  the  end  of  every  trip,  and  is  held  in  that  position 
by  the  arm  7  bearing  against  one  or  the  other  of  the  stop  balls,  8,  9; 
therefore,  unless  the  piston  moves  away  from  the  end  far  enough  to 
permit  the  stop  ball  to  move  the  valve,  B"  will  remain  closed,  so  that 
the  opening  of  the  main  valve  would  not  have  any  effect  in  starting  the 
elevator.  With  the  segment  50  made  so  as  to  have  considerable  play  in 


58  HYDRAULIC  ELEVATORS 

the  supporting  flanges  of  the  hubs  49,  as  is  clearly  shown  in  Fig.  40, 
there  is  no  difficulty  in  making  a  start,  because  when  the  elevator  is 
stopped,  the  current  of  water  flowing  through  B"  is  in  such  a  direction 
as  to  press  the  segment  50  against  the  casing  51,  and  when  the  main 
valve  is  moved  so  as  to  run  the  elevator  in  the  opposite  direction,  the 
pressure  of  the  water  acting  on  B"  will  be  toward  the  center  of  the  circle 
and  thus  will  push  50  away  from  51,  and  permit  a  sufficient  amount  of 
water  to  leak  through  to  start  the  car  gradually.  As  soon  as  the  car 
begins  to  move,  the  arm  7  permits  the  stop  ball  to  return  to  the  normal 
position,  and  then  the  weight  ip  draws  the  gear  77,  and  thereby  the 
valve  B"  into  the  open  position.  From  this  it  will  be  seen  that  this  valve 
not  only  acts  as  an  automatic  limit  stop,  but  also  it  provides  means 
whereby  the  car  is  prevented  from  starting  off  with  a  violent  jerk  if  the 
operator  moves  the  lever  too  rapidly  to  the  full-speed  position. 

SPEED-REGULATING  VALVE. 

The  construction  and  principle  of  action  of  the  speed-regulating  valve 
B',  shown  in  Fig.  32,  will  be  more  fully  understood  by  reference  to  the 
line  drawing  Fig.  42,  which  is  a  section  parallel  with  the  axis  of  the 
valve-rod.  The  port  63  is  bolted  against  the  upper  end  of  the  cylinder, 
while  the  circulating  pipe  is  screwed  into  the  lower  end  62,  thus  whether 
water  is  passing  from  the  pressure  tank  into  the  upper  end  of  the 
cylinder,  or  the  water  is  simply  circulating  from  the  upper  end  to  the 
lower  end  of  the  cylinder,  it  must  pass  through  this  speed-regulating 
valve.  Suppose  the  elevator  is  running  upward,  then  water  will  pass 
from  the  pressure  tank,  up  through  the  regulating  valve  to  the  upper 
end  of  the  cylinder.  This  current  of  water  will  strike  against  the  lower 
end  of  the  valve  70,  and  push  it  upward  against  the  tension  of  the 
spring  71.  If  the  elevator  is  running  down,  the  stream  of  water  will 
flow  from  the  port  63  down  through  the  regulator  and  into  the  circu- 
lating pipe.  In  this  case  the  force  of  the  water  will  act  against  the  top 
of  the  valve  70  against  the  tension  of  the  spring  J2.  By  properly 
adjusting  these  springs  the  device  can  be  arranged  so  as  to  act  at  any 
desired  velocity.  The  action  depends  entirely  upon  the  velocity  of  the 
water  flowing  through  the  valve;  therefore,  it  is  not  affected  by  any 
variations  that  may  occur  in  the  pressure  of  water.  The  operation  of 
the  valve  is  so  self-evident  as  to  require  no  very  extended  explanation. 
It  can  be  seen  that  on  the  down  stroke  of  the  piston,  if  the  valve  is 
forced  upward  far  enough  by  the  impact  of  the  stream  of  water,  the 
upper  end  will  enter  the  neck  75,  and  thus  gradually  reduce  the  opening 
through  which  the  water  must  pass,  and  thereby  reduce  the  volume  that 
passes,  hence  the  velocity.  On  the  up-stroke  of  the  piston,  the  valve  is 


PILOT- VALVE  CONTROL — REGULATING  VALVES  59 

forced  down  into  the  neck  74,  of  the  valve  chamber.  The  interior  valve 
6?  is  for  the  purpose  of  preventing  too  sudden  a  movement  of  the  valve 
70;  that  is,  it  acts  as  a  dash-pot.  The  packings  68  make  a  tight  joint,  and 
the  proper  amount  of  leakage  to  give  the  desired  retardation  is  obtained 
by  providing  the  necessary  difference  between  the  diameter  of  the  rod 
64  and  the  holes  through  the  ends  of  the  valve.  The  springs  71  and  72 
can  be  compressed  more  or  less,  as  may  be  required,  by  means  of  the 
adjusting  sleeves  at  their  ends. 


CHAPTER  X 
SAFETY  DEVICES 

The  safety  device  shown  on  the  car  in  Figs.  32  and  33  is  of  the  clamp, 
or  brake,  type.  It  is  known  as  the  "Otis  wedge-clamp  safety,"  and  its 
construction  and  operation  can  be  fully  understood  from  Fig.  43  and 
the  line  drawings  that  follow.  The  lower  part  of  Fig.  43  shows  the 
under  side  of  the  elevator  car,  with  the  safety  attached  thereto.  The 
center  portion  shows  the  roof  of  the  car  and  the  device  placed  thereon 
to  hold  the  governor  rope.  The  upper  portion  shows  the  safety  governor, 
whose  office  is  to  actuate  the  safety.  For  the  purpose  of  showing  clearly 
the  construction  of  the  safety,  the  side  of  the  framing  that  is  in  front 
of  these  parts  is  drawn  as  if  it  were  transparent,  and  while  this  type  of 
illustration  serves  admirably  to  accomplish  the  object  intended,  it  is 
liable  to  be  misleading  if  it  is  not  kept  in  mind  that  this  side  is  made  of  a 
channel  beam,  so  that  in  the  actual  apparatus  the  internal  parts  cannot 
be  seen  at  all.  The  operation  of  the  safety  is  as  follows : 

The  end  pieces  26  form  powerful  clamps  that  are  pressed  against  the 
same  elevator  guides  that  the  guide-shoes  12  run  on.  At  the  inner  ends 
of  these  clamps  rollers  80  are  mounted,  and  between  these  wedge-shaped 
pieces  fp  are  forced  by  the  rotation  of  the  drum  25.  The  forcing  of 
these  wedges  between  the  rollers  80  spreads  the  inner  ends  of  the  clamps 
26  and  forces  the  outer  ends  against  the  elevator  guides,  thus  developing 
a  frictional  resistance  that  increases  gradually  as  the  pressure  of  the 
clamps  is  increased,  until  the  car  is  brought  to  a  stop.  The  rotation  of 
the  drum  <?5  causes  the  shafts  78  to  move  outward,  and  thus  force  the 
wedges  /p  into  the  space  between  the  rollers  80.  The  drum  25  is  rotated 
by  the  rope  //,  and  this  rope  is  actuated  by  the  safety  governor  in  the 
following  manner :  The  governor  rope  10  is  in  effect  endless,  as  shown 
in  Figs.  32  and  33,  its  ends  being  fastened  to  the  piece  10'.  This  piece 
has  conical  projections  on  its  sides  that  fit  into  depressions  in  the  ends, 
of  the  levers  10" '.  These  levers  are  pivoted  at  iolt  and  their  back  ends 
are  forced  apart  by  a  spring  io3.  The  tension  of  this  spring  is  sufficient 
to  hold  the  levers  10'  firmly  enough  to  drive  the  safety  governor;  so 
that  in  the  normal  running  of  the  elevator  the  parts  remain  in  the 
position  in  which  they  are  shown,  and  the  governor  is  driven  at  a  speed 
that  corresponds  with  the  velocity  of  the  car. 

60 


10 


FIG.   43 


62 


HYDRAULIC  ELEVATORS 


The  stand  io2  holds  two  small  sheaves,  in  addition  to  the  levers  10", 
and  the  rope  n  passes  over  the  lower  sheave  and  around  the  top  one,  its 
end  coming  forward  and  being  firmly  secured  to  10',  at  the  point  n",  as 
shown  in  the  illustration.  If  the  elevator  car  attains  a  velocity  higher 
than  that  for  which  the  governor  has  been  adjusted,  the  balls  will  swing 
outward  so  far  that  the  lifting- rod  will  throw  the  rope  clamps  into  action, 


FIG.  44 


FIG.  45 

and  thus  immediately  stop  the  movement  of  the  latter.  As  the  car  still 
continues  to  move,  the  piece  id  is  pulled  away  from  the  ends  of  levers  10" 
and  then  the  rope  n  is  drawn  upward  and  the  drum  25  is  rotated.  As 
soon  as  the  drum  begins  to  rotate,  the  pressure  of  the  clamps  26  is  applied 
to  the  elevator  guides,  and  the  farther  the  car  moves  after  this  action,  the 
more  the  drum  rotates  and  the  tighter  the  clamps  are  applied,  until  the 
braking  force  becomes  sufficient  to  stop  the  car. 


SAFETY  DEVICES  63 

I 

A  very  good  feature  of  all  these  clamp  safety  devices  is  that  they 
cannot  stop  the  car  suddenly,  but  in  every  case  the  retardation  is  gradual, 
so  that  the  car  may  not  be  brought  to  a  state  of  rest  in  less  than  three 
or  more  feet.  If  the  governor  rope  10  and  the  drum  driving  rope  // 
are  sufficiently  strong,  and  in  good  condition,  the  safety  is  sure  to  stop 
the  car,  because  the  farther  it  moves  the  greater  will  be  the  pressure  of 
the  clamps  26  against  the  elevator  guides,  so  that  after  a  while  the 
braking  force  must  become  great  enough  to  overbalance  the  momentum 
of  the  moving  mass. 

The  construction  of  the  several  parts  of  this  safety  can  be  better 
understood  from  the  line  drawings  Figs.  44  and  45,  the  first  being  a  side 


FIG.  46 


FIG.  47 


view  and  the  second  a  plan.  The  brake  clamps  26  are  hinged  on  a  strong 
steel  stud  81,  and  carry  at  their  inner  ends  rollers  80.  The  wedge-shaped 
pieces  79  are  mounted  on  the  ends  of  the  shafts  78  and  are  prevented 
from  getting  out  of  line  by  side  guides.  The  shafts  f8  are  prevented 
from  turning  by  pins  that  slide  in  slots  in  the  bearings  in  which  they  are 
held,  as  is  shown  in  Fig.  45.  The  inner  sleeves  of  the  drum  are  threaded 
to  fit  the  screw  ends  of  the  shafts  7$,  with  right-  and  left-hand 
threads,  so  that  when  the  drum  rotates  the  shafts  are  forced  outward, 
and  the  wedges  79  are  driven  in  between  the  rollers  80,  thus  forcing  the 
outer  ends  of  the  clamps  26  together,  with  an  ever-increasing  force. 
The  bevel  gear  82  at  the  end  of  the  drum  is  for  the  purpose  of  releasing 


64 


HYDRAULIC  ELEVATORS 


the  clamps  after  the  safety  has  gone  into  action.  This  gear  is  used  in 
connection  with  a  wrench  that  consists  of  a  pinion  #J,  shown  in  broken 
lines  in  Fig.  44,  mounted  on  the  lower  end  of  a  stem  84  that  is  con- 
structed at  the  top  with  a  handle  #5.  A  trap-door  is  provided  in  the 
car,  and  by  removing  this  the  wrench  can  be  put  in  position  and  by 
means  of  it  the  drum  can  be  turned  backward  to  the  normal  position  so 
as  to  release  the  clamps  26. 

Fig.  44  also  shows  the  construction  of  the  elevator  guide-shoes  12. 
As  will  be  noticed,  these  are  provided  with  adjusting  screws,  and  as 
they  work  on  a  swivel,  they  can  be  set  so  as  to  have  but  little  play. 


FIG.  48 

On  this  account  the  brake  clamps  26  can  also  be  set  close  without  fear 
of  their  rubbing  against  the  elevator  guides  and  thus  getting  so  loose 
that  the  clamp  will  not  act  soon  enough,  or  with  sufficient  force  when 
called  into  action. 

In  Fig.  32  it  will  be  noticed  that  there  is  a  second  lever  in  the  car  on 
the  right  side  of  the  operating  lever.  This  is  an  emergency  lever  used 
in  most  first-class  elevators  to  enable  the  operator  to  retard  or  even  stop 
the  car,  if  for  any  reason  he  cannot  control  it  by  means  of  the  regular 
lever.  The  construction  of  this  device  (which  is  simply  an  addition  to 
the^  clamp  safety)  and  its  operation  can  be  understood  from  the  drawings 
Figs.  46,  47  and  48,  the  first  of  which  is  an  elevation  giving  a  side  view 
of  the  main  and  the  emergency  levers.  Fig.  47  is  an  elevation  at  right 


SAFETY  DEVICES  65 

y 

angles  to  Fig.  46,  looking  at  the  latter  from  the  left  side,  and  gives  an 
edge  view  of  the  two  levers.  Fig.  48  is  a  plan  of  one-half  of  a  car, 
showing  the  safety  device  and  the  connecting-rods  and  links  connecting 
in  with  the  emergency  lever,  in  broken  lines.  In  this  arrangement,  the 
shafts  f8t  are  made  in  two  parts  and  are  joined  by  the  hubs  of  the  cranks 
94,  the  latter  having  right-  and  left-hand  threads  in  their  bore,  into 
which  the  ends  of  78  are  screwed.  When  the  emergency  lever  86  is 
moved  toward  the  position  86' ,  it  acts  through  the  connecting  levers  and 
rods  to  turn  the  cranks  94  in  the  direction  that  will  force  the  ends  of  78 
out,  spread  the  wedges  79  and  apply  the  brake  clamps  26.  The  several 
cranks  and  connecting-rods  are  numbered  consecutively,  so  that  following 
the  numbers  the  way  in  which  the  motion  of  86  is  transmitted  to  94  can 
be  easily  traced.  This  device  can  be  used  to  stop  the  car  if  the  lever  86 
is  moved  far  enough,  but  it  would  be  better  to  apply  it  with  enough 
force  to  simply  retard  the  velocity  of  the  car  to,  say,  half  speed  or  less, 
and  thus  descend  safely  to  the  bottom  floor  of  the  building 


CHAPTER  XI 

GOOD  FEATURES  OF  MAGNETIC  VALVE  CONTROL;  OBSTA- 
CLES THAT  PREVENT  ITS  GENERAL  USE— DESCRIP- 
TION OF  CONTROL  SYSTEMS 

The  running-rope  and  standing-rope  arrangements  for  moving  the 
pilot  valves  of  hydraulic  elevators  enable  the  operator  to  control  the 
movement  of  the  car  perfectly,  i.  e.,  to  cause  it  to  run  at  any  desired 
speed,  from  maximum  to  a  barely  perceptible  motion,  and  to  start  and 
stop  as  slowly  or  rapidly  as  he  may  desire;  but,  structurally  considered, 
these  arrangements  are  not  entirely  free  from  objection.  Comparing 
them  with  the  simple  hand  rope,  it  can  be  seen  that  they  have  several 
additional  parts,  and  this  alone  increases  the  first  cost  and  makes  them 
more  expensive  to  maintain.  In  practice,  however,  their  operation  has 
proved  entirely  satisfactory,  with  the  single  exception  of  their  liability 
to  get  out  of  adjustment  through  the  stretching  of  the  ropes.  When  in 
proper  adjustment,  the  car  lever  will  stand  vertical  when  the  valve  is 
closed.  If  when  the  ropes  stretch  they  both  lengthen  out  the  same 
amount,  the  adjustment  will  not  be  disturbed,  and  the  fact  that  the  ropes 
have  stretched  will  not  be  noticed,  as  the  tension  weight  will  take  up  the 
slack ;  but  if  one  rope  lengthens  out  more  than  the  other,  then  the  car 
lever  will  not  stand  vertical  when  the  valve  is  closed,  but  will  incline  to 
one  side  or  the  other.  If  the  difference  in  the  stretch  of  the  ropes  is 
not  great,  the  "stop"  position  of  the  lever  will  vary  so  little  as  to  make 
no  difference  in  the  operation  of  the  car ;  but  in  some  cases  the  lever 
will  stand  several  inches  from  the  central  position  when  the  car  is 
stopped,  and  then  it  becomes  necessary  to  readjust  the  ropes.  This  is 
accomplished  by  taking  up  the  rope  that  has  stretched  the  more,  until 
the  car  lever  is  brought  to  the  central  position,  when  the  valve  is  closed. 
When  the  ropes  are  new  they  may  require  frequent  adjustment,  but 
after  a  few  months'  operation  practically  all  the  stretch  will  have  been 
taken  out  of  them,  after  which  slight  trouble  will  be  experienced. 

As  the  standing-rope  and  running-rope  systems  comprise  considerable 
mechanism,  it  has  been  thought  that  some  sort  of  magnetically  operated 
device  could  be  used  that  would  be  far  more  simple  and  compact,  and 
certainly  easier  to  handle,  as  a  small  electric  switch  could  be  substituted 

66 


GOOD  FEATURES  OF  MAGNETIC  VALVE  CONTROL  67 

for  the  operating  lever.  This  would  be  a  decided  gain  in  buildings 
where  many  passengers  are  carried,  since  considerable  room  is  required 
for  the  proper  manipulation  of  the  operating  lever,  while  for  the  move- 
ment of  a  small  electric  switcty  very  little  space  is  needed.  Another 
advantage  would  be  that  the  ropes  and  sheaves,  which  take  up  quite  a  lot 
of  space,  would  be  replaced  by  small  wires  which  could  be  located  in 
any  convenient  position,  the  connection  with  the  car  being  made  through 
a  flexible  cable  similar  to  that  used  for  conveying  current  for  incan- 
descent lamps. 

Many  inventors  have  endeavored  to  produce  an  electric  controller,  but 
up  to  the  present  no  one  has  brought  out  anything  that  is  of  sufficient 
merit  to  enable  it  to  replace  the  mechanical  devices  generally  applied  to 
first-class  elevators  in  large  office  buildings.  The  principal  objection  to 
magnetic  controllers  is  that  they  do  not  enable  the  operator  to  control 


Dg  FIG.  49 


FIG.  50 


the  movement  of  the  car  as  closely  as  can  be  done  with  either  the 
standing-rope  or  the  running-rope  method.  Another  objection  is  that 
they  are  more  liable  to  get  out  of  order.  For  these  reasons,  then,  these 
controllers  are  not  generally  used  for  passenger  elevators  in  large  build- 
ings. Nevertheless,  they  have  a  field  of  their  own  in  which  they  are 
decidedly  superior  to  mechanical  devices,  and  in  which  they  have  prac- 
tically superseded  all  other  methods  of  control. 

In  many  buildings  owned  by  insurance  companies  and  other  large 
corporations,  elevators  and  dumb-waiters  have  been  installed  for  the 
exclusive  use  of  officers  or  employees.  Such  elevators  are  not  in  con- 
stant use,  and  therefore  are  not  provided  with  operators,  but  each 
passenger  operates  the  elevator  himself.  As  every  one  who  desires  to 
use  the  car  cannot  be  expected  to  be  an  experienced  elevator  operator  it 
is  necessary  to  provide  a  controller  so  simple  that  any  one  can  use  it, 


68 


HYDRAULIC  ELEVATORS 


and  this  simplicity  can  be  easily  obtained  in  the  magnetic  controllers, 
which  require  only  a  switch  or  push-button  at  each  floor,  and  similar 
devices  in  the  car. 

MAGNETICALLY  CONTROLLED  PILOT  VALVE. 

A  magnetically  controlled  pilot-valve  gear,  such  as  is  used  under 
such  circumstances,  is  shown  in  Fig.  49.  The  operation  of  this  device 
is  as  follows:  The  lever  A  is  actuated  by  the  pull  of  the  magnets  M 
and  M',  which  attract  the  armature  B  and  B'  when  an  electric  current 
is  passed  through  the  magnet  coils.  The  arm  A',  extending  downward 
from  A,  is  held  between  the  two  horizontal  rods  C  and  Cr,  which  are 
pressed  against  it  by  the  springs  ^  and  S'.  The  nuts  D  and  D',  together 
with  the  threaded  joint  in  rod  zj,  comprise  means  for  adjusting  the 


FIG.  51 


FIG.  52 


position  of  the  pilot  valve,  the  rod  being  set  when  the  mechanism  is  put 
together,  and  the  nuts  being  used  for  the  final  adjustment. 

The  magnets  are  of  the  horse-shoe  type,  there  being  two  coils  each 
in  M  and  M'.  The  armatures  B  and  B'  are  long  enough  to  cover  both 
poles  in  the  magnets.  By  comparing  Fig.  49  with  the  mechanically 
operated  pilot  valve,  it  will  be  seen  that  the  magnets  M  and  M'  displace 
the  rope  sheave,  and  the  lever  A  displaces  the  crank  on  the  end  of  the 
sheave  shaft.  In  all  other  respects  the  two  arrangements  are  the  same; 
the  pilot  valve,  however,  is  solid  in  the  magnetically  operated  system, 
instead  of  being  provided  with  cup  packings.  This  difference  is  made 
in  order  that  the  valve  may  move  more  easily,  and  therefore  not  require 


GOOD  FEATURES  OF  MAGNETIC  CONTROL  69 

the  use  of  excessively  large  magnets.  This  solid  pilot  valve  is  hardened 
and  ground  to  insure  a  perfect  fit.  Its  actual  construction  is  not  clearly 
shown  in  Fig.  49,  but  will  be  fully  understood  from  the  enlarged  illus- 
tration, Fig.  50.  The  lower  end  E  is  of  the  same  diameter  as  the  body 
of  the  valve  Vs,  in  order  to  prevent  springing  and  the  consequent  wear- 
ing of  the  edges  of  the  port  recessed  in  the  valve  chamber.  To  provide 
an  opening  for  the  water  to  escape  through  the  lower  end  of  the  chamber 
into  the  discharge  tank,  the  enlarged  end  E  is  cut  away  at  four  places,  as 
clearly  shown. 

As  the  pull  of  the  magnets  is  limited,  it  is  necessary  to  guard  against 
the  entrance  of  chips  or  other  solids  into  the  valve,  because  these  might 
be  caught  between  the  latter  and  the  edges  of  the  ports  in  the  valve 
chamber  and  lock  the  valve.  For  this  purpose  strainers  are  provided 
through  which  all  the  water  passes  to  the  pilot  valve.  The  way  in  which 
these  strainers  are  connected,  and  the  general  arrangement  of  the  entire 
valve-actuating  piping,  are  fully  shown  in  Figs.  51  and  52.  Two  strainers 
are  provided,  so  that  it  may  not  be  necessary  to  stop  the  elevator  to 
clean  them.  Only  one  of  the  strainers  is  in  use  at*  a  time,  the  two  three- 
way  cocks  being  provided  for  the  purpose  of  connecting  either  strainer 
with  the  piping.  The  one  out  of  service  can  be  opened  and  cleaned  at 
any  time.  The  lower  end  of  the  bottom  three-way  cock  is  connected  with 
the  pressure  tank  through  the  pipe  K,  and  the  lower  end  of  the  pilot- 
valve  chamber  is  connected  with  the  discharge  tank  through  pipe  /• 
The  rest  of  the  piping  is  so  clearly  shown  as  to  require  no  explanation. 


CHAPTER  XII 
MAGNETIC  CONTROLLER  FOR  BATTERY  CURRENT 

The  controller  shown  in  Fig.  49  is  intended  for  use  in  buildings 
where  there  is  a  direct-current  incandescent-light  circuit;  but  in  cases 
where  such  a  circuit  is  not  available  the  magnets  must  be  operated  by 
current  derived  from  primary  or  storage  batteries,  and  as  such  currents 
are  expensive  it  is  necessary  to  modify  the  construction  of  the  controller 
so  that  it  may  be  operated  with  less  current.  The  way  in  which  this  is 
accomplished  is  shown  in  Fig.  53,  which  shows  the  Otis  magnet  con- 
troller for  battery  current.  This  controller  is  also  used  for  alternating 
currents,  the  magnets  being  of  the  solenoid  type.  The  principal  differ- 
ence between  Figs.  49  and  53  is  that  in  the  latter  are  two  secondary  pilot 
valves  D'  which  are  much  smaller  than  the  regular  pilot  valve  and  there- 
fore can  be  moved  with  much  less  effort.  These  valves  control  the  flow 
of  water  into  and  out  of  the  cylinder  Z,  so  as  to  push  the  piston  up  or 
down,  as  may  be  required.  The  movement  of  the  piston,  through  the 
rod  Jj  and  the  lever  4,  actuates  the  main  pilot  valve.  The  weight  of  W  is 
for  the  purpose  of  balancing  the  weight  of  the  lever  4  to  the  right  of  rod 
75,  and  also  the  pilot  valve  and  connection  rods.  The  weight  W  is  for 
the  purpose  of  counterbalancing  the  weight  of  W,  the  lever  4  and  the 
pilot  valve  and  connections. 

The  construction  of  the  secondary  pilot  valves  D'  can  be  understood 
from  Fig.  54,  which  is  a  section  through  the  valve  chambers  taken  at 
right  angles  to  the  view  in  Fig.  53.  The  two  pairs  of  solenoid  magnet 
coils  act  independently  of  each  other  on  the  two  valves  D'  and  D2,  and 
when  they  are  not  energized  the  valves  rest  in  the  position  in  which 
they  are  drawn  in  Fig.  53,  so  as  to  connect  the  ports  a  and  b.  The 
ports  a  a'  are  connected  with  the  opposite  ends  of  the  auxiliary  cylinder 
Z,  while  the  ports  b  are  connected  through  the  central  passage  in  the 
valve  casting  with  a",  and  thus  with  the  discharge  pipe.  If  the  magnets 
M  M,  Fig.  53,  are  energized,  the  valve  D'  will  be  drawn  down  and  then 
port  a  will  be  connected  with  c,  which,  as  shown  in  Fig.  55,  is  connected 
with  the  supply  pipe ;  therefore,  pressure  water  will  pass  to  a  and  thus 
to  the  upper  end  of  Z,  and  force  the  piston  down  against  the  tension  of 
the  spring  S'.  Thus  the  pilot  valve  43  will  be  depressed  and  the  pressure 

70 


72  HYDRAULIC  ELEVATORS 

water  will  pass  through  the  pipe  E,  to  the  upper  end  of  the  main  valve 
chamber. 

If  the  magnets  M'  M'  are  energized,  the  valve  D2  will  be  pushed 
down,  and  then  the  pressure-water  port  c  will  be  connected  with  a',  and 
thus  with  the  lower  end  of  Z,  thereby  forcing  the  rod  ij  upward  against 
the  tension  of  the  spring  S',  Fig.  53.  This  spring  is  made  stiff  enough 
to  force  the  compression  rings  Q  Q'  against  the  stops  and  thus  bring 
the  pilot  valve  to  the  central  position  whenever  the  current  is  cut  off 
from  either  pair  of  magnets.  The  sleeves  P  P'  limit  the  movement  of 
the  rod  /j  and  thus  the  stroke  of  the  pilot  valve  43.  The  pilot  valve 
and  valves  D'  D2  are  made  to  fit  tightly  by  grinding,  but  not  too  tightly, 
so  they  may  move  as  easily  as  is  consistent  with  a  good  fit.  D'  D2 


FIG.  54 

do  not  have  to  fit  as  closely  as  the  pilot  valve ;  for  even  if  they  leak 
considerably  the  only  effect  is  to  waste  a  small  amount  of  water,  because 
when  in  the  stop  position  they  both  connect  with  the  discharge  pipe. 
Hence,  after  filling  both  ends-  of  the  cylinder  Z,  the  additional  leakage 
would  pass  to  the  discharge.  Owing  to  this  fact  these  valves  can  be 
made  so  as  to  move  very  easily,  the  principal  resistance  being  in  the 
stuffing-boxes ;  these  should  not  be  screwed  down  any  more  than  is 
necessary  to  make  them  tight,  and  a  soft  packing  should  be  used  in  them. 

Figs.  56  and  57  are  external  views  of  the  parts  shown  in  Figs.  53  and 
49,  respectively,  and  will  serve  to  show  more  clearly  the  arrangement, 
particularly  of  the  pipe  connections  and  the  strainers.  In  Fig.  57  the 
two  magnet  spools  in  front  are  removed  so  as  to  show  clearly  the  con- 
struction of  the  lever  A  with  the  extending  arm  A' ';  also  the  rods  C  C 
and  the  tension  springs  S  Sr. 

Magnetically  operated  valves  have  to  be  arranged  so  that  they  can  be 
easily  handled  by  persons  who  are  not  skilled  elevator  operators.  A 


MAGNETIC  CONTROLLER  FOR  BATTERY  CURRENT 


73 


great  many  controlling  devices  of  this  kind  have  been  invented,  and  in 
the  following  paragraphs  will  be  described  two  which  are  quite  exten- 
sively used. 

Fig.  58  is  a  wiring  diagram  of  a  simple  controller,  by  means  of  which 
the  car  can  be  operated  from  any  floor  of  the  building  as  well  as  from 
within  the  car.  The  controller  circuit  is  connected  with  the  supply 
wires  P  and  N  by  means  of  a  two-pole  switch  shown  at  the  left  side  of 
the  diagram.  If  this  switch  is  closed  and  the  controller  switches  are  all 


Conuect  with 
Suj.ply  Pipe 


FIG.   55 


open,  as  is  the  case  when  the  car  is  not  running,  the  current  can  pass 
from  P  to  the  wire  A,  then  up  the  elevator  well  to  the  several  floors  of 
the  building,  and  return  by  the  wire  B,  passing  through  the  door-contact 
switches  B'  at  each  floor,  and  thence  to  the  wire  B"  and  to  the  lever  of 
the  floor  switch.  One  of  these  floor  switches  is  located  at  each  floor 
from  which  it  is  desired  to  operate  the  elevator.  As  the  floor  switch  is 
open,  the  current  can  go  no  farther.  From  the  wire  A  it  will  be  seen 
that  a  wire  A'  runs  upward;  this  runs  to  a  point  about  half  way  up  the 


74 


HYDRAULIC  ELEVATORS 


elevator  well  and  there  enters  a  flexible  cable,  which  connects  with  the 
elevator  car  and  reaches  the  up  and  down  push-buttons ;  but  it  can  pass 
no  farther,  as  these  push-buttons  do  not  connect  with  either  C"  or  K'. 

If  a  person  at  any  floor  desires  to  use  the  car,  he  operates  the  floor 
switch,  turning  it  so  as  to  set  the  car  in  motion  toward  that  floor. 
Suppose  the  car  is  above  him,  he  then  turns  the  floor  switch  to  the  left 
so  as  to  cause  the  car  to  run  down.  The  current  from  B"  will  pass  to 
C'y  to  K,  to  /,  to  and  through  the  pair  of  down  magnets  on  the  valve  to 


FIG.  56 

the  wire  E',  and  thence  to  the  supply  wire  N.  When  the  car  reaches  the 
floor,  the  passenger  opens  the  floor  switch,  then  the  elevator  inclosure 
door,  and  steps  into  the  car.  The  opening  of  the  inclosure  door  releases 
one  of  the  floor-contact  switches  B'  and  thus  breaks  the  circuit,  so  that 
the  car  cannot  be  moved  until  the  door  is  closed  again.  After  the  pas- 
senger has  entered  the  car  and  has  closed  the  landing  door,  he  can  cause 
the  car  to  run  either  up  or  down  by  simply  pressing  the  proper  push- 
button and  keeping  it  pressed  in  until  the  car  reaches  the  floor  at  which 


MAGNETIC  CONTROLLER  FOR  BATTERY  CURRENT 


75 


he  desires  to  stop.  If  he  desires  to  go  down  he  presses  the  lower  button, 
when  the  current  passes  from  A'  to  K',  thence  to  K  and,  through  the 
route  as  before  explained,  to  the  wire  N. 

This  arrangement  is  very  simple,  but  has  two  objections,  one  of 
which  is  that  the  passenger  has  to  hold  the  floor  switch  (or  the  car 
button)  closed  until  the  car  reaches  the  floor,  and  has  to  use  his  judgment 
in  determining  just  how  far  the  car  may  be  from  the  floor  when  he 
opens  the  switch,  so  that  it  will  stop  even  with  the  landing.  Another 
objection  is  that  when  a  passenger  is  already  in  the  car  some  one  else, 


FIG.  57 

at  one  of  the  floors,  can  interfere  with  its  operation  by  turning  the 
floor  switch  so  as  to  produce  the  opposite  movement  of  the  car.  In  the 
same  way  a  passenger  in  the  car  can  interfere  with  any  movement 
directed  from  a  landing. 

The  wiring  diagram  Fig.  59  shows  a  more  complicated  arrangement 
than  that  just  explained,  but  is  far  superior  to  it,  as  it  is  entirely  non- 
interfering  ;  and  at  the  same  time  it  simplifies  the  work  of  the  passenger, 
for  if  he  is  at  any  floor  and  desires  to  use  the  elevator,  he  has  only  to 


76  HYDRAULIC  ELEVATORS 

press  a  button  for  an  instant,  when  the  car  will  be  set  in  motion, 
whether  above  or  below  him,  and  will  come  to  a  stop  when  it  is  even 
with  his  floor.  After  entering  the  car  and  closing  the  landing  door,  all 
he  has  to  do  is  to  press,  for  an  instant,  the  button  corresponding  with 
the  floor  to  which  he  wishes  to  go,  and  the  car  will  at  once  start  off  and 
stop  automatically  at  that  floor.  The  arrow  heads  on  the  lines  of  the 
diagram  show  how*  far  the  circuits  are  complete  when  the  car  is  not 


FIG.  58 

running.  The  floor  controller  is  a  change-over  switch  arrangement,  the 
object  of  which  is  to  reverse  the  connections  between  the  wires  con- 
necting with  the  push-buttons  at  the  several  floors  and  in  the  car,  and 
with  the  brushes  E  E,  as  the  car  passes  above  or  below  the  floor ;  so 
that  by  means  of  a  single  button  the  car  may  be  made  to  run  down,  if 
above  the  floor,  or  to  run  upward,  if  below  the  floor.  The  relay  magnets 
are  for  the  purpose  of  rendering  it  possible  to  keep  the  elevator  in 


MAGNETIC  CONTROLLER  FOR  BATTERY  CURRENT 


77 


motion  until  the  proper  floor  is  reached,  without  having  to  keep  the 
push-button  depressed.  It  will  be  noticed  that  a  wire  runs  from  /  up 
to  the  contacts  opposite  the  four  relays.  If  any  one  of  the  push-buttons 
is  depressed,  the  current  will  flow  through  the  corresponding  relay 
magnet,  the  contacts  at  the  right  will  be  drawn  up  and  a  direct  connec- 
tion will  be  made  with  point  /.  Thus,  suppose  button  2  P  is  pressed ; 
the  current  will  at  once  pass  through  the  relay  22  and  the  contacts  on 
the  right  side  will  be  closed,  so  that  the  current  may  flow  through  from 
the  junction  point  at  /.  The  floor  controller  revolves,  being  driven  by 


Valve 
Magnets 


Carbon 


FIG.   59 


the  elevator,  and  is  so  geared  that  it  makes  the  upper  end  of  the 
contact  arc  C  travel  from  the  position  in  which  it  is  drawn  (when  the 
car  is  at  the  bottom  of  the  well)  to  the  point  d,  when  the  car  is  at  the 
top  floor.  From  this  it  will  be  seen  that  if  the  button  2  P  is  pressed,  the 
car  will  run  until  the  upper  end  of  the  contact  curve  C  passes  from 
under  the  brush  22}  and  then  the  car  will  stop,  and  it  will  be  even  with 
the  second  floor. 

The  two  coils  between  the  wires  A  and  B  form  a  differentially  wound 
magnet  which  exerts  no  effort  when  the  current  passes  through  both 


78  HYDRAULIC  ELEVATORS 

coils,  and  hence  does  not  draw  apart  the  contacts  at  the  right  side;  but 
if  one  of  the  buttons  is  pressed,  the  instant  the  circuit  from  the  junction 
/  through  the  relay  is  closed,  the  right-side  coil  of  the  differential  magnet 
becomes  inactive,  and  then  the  switch  contacts  are  drawn  apart  and  no 
current  can  pass  to  the  wire  B,  so  that  after  this  time  it  makes  no 
difference  how  much  the  push-buttons  may  be  manipulated,  they  can 
have  no  effect  upon  the  running  of  the  car.  The  circles  a  a  a  a  represent 
inclosure-door  switches  at  the  landings,  which  are  provided  as  safety 
devices  to  prevent  absent-minded  persons  from  moving  the  car  away 
from  the  landing  without  first  closing  the  door. 

While  Fig.  59  is  shown  arranged  to  be  operated  by  a  battery,  Fig.  58 
is  connected  with  supply  wires,  which  may  create  the  impression  that  it 
is  for  use  in  cases  where  the  current  is  derived  from  a  lighting  circuit. 
As  a  matter  of  fact,  however,  both  arrangements  can  be  used  with 
current  derived  from  any  source,  providing  it  is  not  alternating  current ; 
for  the  latter,  slight  modifications  are  made. 

An  examination  of  these  wiring  diagrams,  as  well  as  the  drawings 
49  and  53,  will  show  at  once  that  these  magnetic  valve-operating  devices 
open  the  valve  wide  to  set  the  car  in  motion,  and  close  it  entirely  in 
one  movement  when  the  car  is  to  be  stopped.  The  person  operating 
the  elevator  cannot  in  any  way  vary  the  running  speed,  nor  can  he  cause 
the  car  to  get  under  headway  either  quickly  or  gradually  at  will,  nor 
make  a  quick  stop  or  a  slow  one;  all  he  can  do  is  to  open  the  valve  to 
start,  and  close  it  to  stop.  The  speed  the  car  will  take  will  depend  entirely 
upon  the  way  in  which  the  valves  are  adjusted,  and  this  is  true  as  to  the 
rate  of  acceleration  in  starting  and  of  retardation  in  stopping.  This  lack 
of  flexibility  is  the  reason  why  magnetic  valve-control  has  not  come  into 
general  use  for  passenger  elevators.  Some  magnet  controllers  have  been 
devised  that  partially  accomplish  the  results  obtained  with  the  mechanical 
devices,  but  they  are  complicated  and  cannot  be  regarded  as  entirely 
practical. 


CHAPTER  XIII 
DOUBLE-POWER  HYDRAULIC  ELEVATOR  SYSTEM 

In  Fig.  24  we  presented  a  diagram  illustrating  the  double-power 
system  of  hydraulic  elevators,  an  arrangement  devised  to  reduce  the 
power  consumption,  and  make  it  more  nearly  proportional  to  the  actual 
amount  of  work  done.  With  a  steam  or  electrically  driven  elevator,  the 
power  required  is  directly  proportional  to  the  load  lifted,  and  it  cannot 
very  well  be  otherwise;  in  other  words;  it  is  "the  nature  of  the  beast"  to 
put  forth  an  effort  equal  to  the  work  it  has  to  do  and  no  more.  With 
hydraulic  elevators  this  is  not  the  case,  for  the  simple  reason  that  to  run 
the  elevator  car  from  the  bottom  to  the  top  of  the  building  requires  one 
cylinder  full  of  water,  regardless  of  whether  the  car  is  empty  or  fully 
loaded.  The  lifting  capacity,  however,  must  be  sufficient  to  run  the  car 
up  with  the  maximum  load,  and  this  means  that  the  pressure  maintained 
in  the  pressure  tank  must  be  high  enough  to  do  this  maximum  work. 
This  being  the  case,  all  the  water  pumped  into  the  tank  must  be  forced 
against  a  pressure  great  enough  to  elevate  the  car  when  fully  loaded. 
It  may  be  asked,  where  does  the  power  go  to  when  the  car  is  run  up 
light,  since  the  lifting  capacity  of  the  piston  is  sufficient  to  raise  the 
maximum  load  ?  The  answer  is  simply  that  generally  the  surplus  power 
is  absorbed  in  forcing  the  water  at  a  high  velocity  through  the  con- 
tracted opening  in  the  operating  valve,  the  latter  not  being  opened  wide 
under  such  conditions.  If  the  valve  should  be  opened  wide  the  car  will 
run  at  a  higher  speed  than  when  loaded,  and  then  the  surplus  power 
will  be  absorbed  in  forcing  the  water  through  the  piping,  as  well  as  the 
valve,  at  an  increased  velocity.  As  it  is  contrary  to  the  nature  of  the 
hydraulic  elevator  to  use  energy  in  proportion  to  the  work  done,  special 
arrangements  have  to  be  devised  to  accomplish  the  result,  and  although 
these  arrangements  do  not  accomplish  it  perfectly,  they  do  it  well  enough 
to  be  of  decidedly  practical  value. 

The  Otis  double-power  vertical  elevator  is  illustrated  in  Fig.  60.  The 
valves  are  shown  in  the  stop  position.  An  inspection  of  the  drawing 
will  show  that  the  main  valve  and  valve  chamber  are  longer  than  the 
low-pressure  valves  described  in  previous  chapters,  and  in  addition  there 
is  an  extra  valve  piston  F2.  The  upper  outlet  port  of  the  chamber  con- 
nects with  the  lower  end  of  the  circulating  pipe,  and  the  lower  outlet 
port  connects  with  the  bottom  of  the  cylinder.  The  valve  chamber  is 
made  longer  so  as  to  provide  space  for  the  port  of  the  high-pressure  pipe, 

79 


8o 


HYDRAULIC  ELEVATORS 


and  the  valve  is  made  with  the  additional  piston  F2,  so  that  when  the 
valve  is  in  the  position  shown,  or  lower  down,  the  high-pressure  water 
may  not  be  able  to  pass  into  the  cylinder. 


PIG.  60 
OTIS    DOUBLE-POWER    HYDRAULIC     ELEVATOR 

The  operation  of  this  system  on  the  downward  trip  of  the  car  (up 
stroke  of  the  piston)  is  the  same  as  that  of  the  low-pressure  machine; 
that  is,  the  main' valve  is  depressed  so  as  to  uncover  the  port  connecting 


DOUBLE-POWER  HYDRAULIC  ELEVATOR  SYSTEM  81 

with  the  lower  end  of  the  cylinder,  and  then  the  water  above  the  piston 
passes  down  through  the  circulating  pipe,  through  the  valve  chamber  to 
the  under  side  of  the  piston,  and  the  latter  ascends  in  the  cylinder.  On 
the  up  trip  of  the  car,  the  main  valve  is  raised  until  the  port  connecting 
with  the  lower  end  of  the  cylinder  is  uncovered  partly  or  in  whole, 
according  to  the  speed  required,  and  then  the  water  under  the  piston 
escapes  into  the  discharge  pipe  D,  and  pressure  water  from  the  low- 
pressure  pipe  passes  through  the  valve  into  the  circulating  pipe  and  to 
the  upper  end  of  the  cylinder,  thus  forcing  the  piston  down.  If  the 
load  is  less  than  one-half  the  maximum,  the  valve  will  not  have  to  be 
raised  any  farther  than  is  necessary  to  uncover  the  ports  connecting  with 
the  low-pressure  pipe,  as  this  pressure  is  sufficient  to  raise  this  load.  If 
the  load  is  more  than  one-half  the  maximum,  the  low-pressure  water 
alone  will  not  lift  it,  unless  it  is  only  slightly  in  excess,  and  even  then 
the  velocity  of  the  car  will  be  too  slow  to  be  satisfactory.  In  such  a 
case  the  operator  moves  the  operating  lever  farther,  so  as  to  lift  the  main 
valve  higher,  and  by  so  doing  a  portion  of  the  ports  of  the  high-pressure 
valve  is  uncovered ;  that  is,  the  piston  V-  passes  above  the  lower  margin 
of  the  ports,  and  then  water  passes  into  the  valve  chamber  from  the 
high-pressure,  as  well  as  from  the  low-pressure  pipe;  as  a  result  the 
pressure  acting  on  the  piston  is  higher  than  the  pressure  in  the  low- 
pressure  pipe.  If  the  load  is  only  a  trifle  more  than  the  low-pressure 
water  alone  can  lift,  only  a  small  amount  of  water  will  be  drawn  from 
the  high-pressure  pipe,  but  if  the  load  is  nearly  equal  to  the  maximum, 
most  of  the  water  will  be  supplied  by  the  high-pressure  pipe,  while  when 
the  load  is  fully  up  to  the  maximum,  no  water  will  be  drawn  from  the 
low-pressure  pipe. 

From  the  foregoing  explanation  it  can  be  seen  that  no  matter  how 
small  the  load  may  be,  it  will  require  just  as  much  power  to  lift  it  as  it 
would  for  the  heaviest  load  that  the  low-pressure  water  can  raise,  but 
for  any  load  between  the  latter  and  the  maximum  amount  the  elevator 
is  designed  to  raise,  the  power  will  not  be  very  far  from  proportional  to 
the  load.  The  high-pressure  water  is  generally  double  the  low-pressure, 
the  usual  pressures  being  200  and  TOO  pounds,  respectively,  so  that  the 
expenditure  of  energy  is  nearly  in  proportion  to  the  work  done  for  all 
loads  greater  than  one-half  the  maximum. 

When  this  system  was  devised,  it  was  expected  that  in  its  operation 
the  high-pressure  water  upon  entering  the  valve  chamber  would  not  only 
flow  inio  the  cylinder,  but  would  also  back  up  into  the  low-pressure  pipe, 
and  to  prevent  this  action  a  check-valve  was  placed  in  the  low-pressure 
pipe,  as  shown  in  the  drawing.  The  actual  operation  of  these  machines, 
however,  has  shown  that  the  high-pressure  water  does  not  run  back  into 


82  HYDRAULIC  ELEVATORS 

the  low-pressure  pipe,  unless  the  load  is  so  great  as  to  require  a  pressure 
nearly  as  great  as  that  of  the  high-pressure  water,  so  that  for  any  load 
under,  say,  75  per  cent,  of  the  maximum,  the  apparatus  would  operate 
perfectly  if  the  check- valve  in  the  low-pressure  pipe  were  removed.  It 
is  not  very  easy  to  explain  how  water  can  run  into  the  valve  chamber 
from  a  pipe  in  which  the  pressure  is  100  pounds,  when  water  is  running 
in  from  another  pipe  in  which  the  pressure  is  200  pounds,  but  it  is 
nevertheless  a  fact  that  it  does  run  in.  If  it  did  not  run  in  the  speed  of 
the  elevator  car  could  not  be  kept  up  when  the  valve  is  raised  just  far 
enough  to  slightly  open  the  high-pressure  ports.  To  make  this  point 
clear,  suppose  the  load  is  slightly  in  excess  of  what  the  low-pressure 
water  alone  can  lift  at  full  speed ;  then,  if  no  high-pressure  water  is  used, 
the  car  will  rise  at  a  slow  velocity ;  if  now  the  valve  is  raised  so  as  to 
open  the  high-pressure  ports,  say,  5  per  cent,  of  their  full  area,  the  speed 
will  be  at  once  reduced  very  decidedly,  if  the  high-pressure  water  backs 
up  into  the  low-pressure  pipe  and  prevents  water  coming  in  from  that 
source,  because  the  opening  of  the  high-pressure  ports  is  so  small  that 
sufficient  water  to  produce  a  high  speed  cannot  pass  through  them.  In 
actual  practice,  however,  it  matters  little  how  slight  the  opening  of  the 
high-pressure  ports  may  be,  the  effect  is  to  give  an  increased  speed;  and 
if  the  car  lever  is  moved  very  slowly  over  the  portion  of  its  movement 
that  begins  to  open  the  high-pressure  ports,  the  speed  will  be  noticed  to 
increase  slowly  and  evenly  as  the  lever  advances.  This  could  not  be  the 
result  if  the  opening  of  the  high-pressure  ports  had  the  effect  of  stopping 
off  the  flow  from  the  low-pressure  pipe,  for  if  such  were  the  action 
until  the  high-pressure  ports  were  opened  enough  to  permit  water  to 
pass  through  them  in  greater  quantity  than  it  previously  entered  through 
the  low-pressure  ports,  the  speed  would  be  lower  than  with  the  low- 
pressure  alone.  Ele'vator  engineers  who  are  familiar  with  this  problem 
have  theorized  upon  it  in  an  endeavor  to  find  a  plausible  explanation  of 
the  action,  and  while  no  one  ap'pears  willing  to  advance  a  decided  opinion 
upon  the  subject,  the  general  conclusion  is  that  there  is  some  kind  of 
inspirator  or  injector  effect  produced,  or  probably  both  effects  exist  at 
once,  the  high-pressure  water  serving  to  suck  the  low-pressure  water  into 
the  valve  chamber  as  it  rushes  down  past  the  low-pressure  ports,  and 
then,  turning  around  just  above  piston  V,  it  may  rush  into  the  ports 
leading  to  the  circulating  pipe,  and  draw  in  the  low-pressure  water 
with  it. 

In  Fig.  60  it  will  be  noticed  that  there  is  a  relief  valve  at  the  top  of 
the  cylinder,  while  no  such  valve  is  provided  with  the  low-pressure 
machines.  This  difference  is  made  necessary  by  the  presence  of  the 
check-valve  in  the  low-pressure  pipe.  This  valve  is  not  required  in  low- 


DOUBLE-POWER  HYDRAULIC  ELEVATOR  SYSTEM 


pressure  machines ;  therefore,  if  the  car  is  stopped  too  rapidly  on  the 
down  trip  the  water  in  the  upper  end  of  the  cylinder  can  flow  back 
through  the  throttle  valve  into  the  pipe.  With  the  double-power  system 
there  is  no  escape  for  the  water  either  through  the  low-pressure  or  the 


FIG.   6 1 


FIG.  62 


high-pressure  pipes,  hence  a  relief  valve  has  to  be  provided  at  the  top 
of  the  cylinder.  NON-CIRCULATING  VALVES. 

Double-power  hydraulic  elevators  have  been  made  by  the  Otis  com- 
pany with  non-circulating  as  well  as  circulating  valves.  The  former  are 
used  in  cases  where  the  varying  weight  of  the  lifting  ropes  is  compensated 
for  by  the  hight  of  a  column  of  water  rising  in  a  stand-pipe  connected 
with  the  bottom  of  the  cylinder,  the  principle  of  which  is  fully  explained 
in  Chapter  V. 

Fig.  60  shows  the  circulating  type.    The  valve  and  valve  chamber  of 


84  HYDRAULIC  ELEVATORS 

this  type  are  shown  in  Fig.  61.  It  will  be  seen  that  on  the  right  side 
the  top  port  connects  with  the  high-pressure,  and  the  bottom  one  with 
the  low-pressure  pipe.  On  the  left  side  there  are  two  ports,  one  to 
connect  with  the  lower  end  of  the  cylinder,  and  the  other,  which  is  just 
above  it,  to  connect  with  the  circulating  pipe.  The  valve  has  the  cup 
packings  a  and  b  turned  toward  each  other,  so  as  to  hold  the  high- 
pressure  water  between  them  when  the  valve  is  in  the  central  position,  as 
drawn  in  Fig.  60. 

The  valve  chamber  and  valve  for  the  non-circulating  machine  are 
shown  in  Fig.  62,  and  as  will  be  noticed  differ  considerably  from  the 
circulating  type.  In  the  valve  chamber  it  will  be  seen  that  the  high- 
pressure  port  is  below  the  low-pressure,  and  on  the  left  side  there  is  only 
one  port  which  connects  with  the  top  of  the  cylinder.  This  is  the  same 
port,  in  so  far  as  its  position  is  concerned,  as  that  in  Fig.  61,  which 
connects  with  the  lower  end  of  the  cylinder.  The  port  which  in  the 
latter  figure  connects  with  the  circulating  pipe  is  closed  up  in  Fig.  62. 
Looking  at  the  valve  in  Fig.  62  it  will  be  seen  that  the  central  valves 
V  V  that  shut  off  the  flow  of  high-pressure  water  are  different  from  the 
similar  valves  in  Fig.  61.  The  latter  are  made  so  as  to  hold  the  high- 
pressure  water  between  the  two  pistons,  so  that  it  cannot  pass  to  the 
cylinder  until  the  valves  have  been  raised  high  enough  to  carry  V2  above 
the  lower  edge  of  the  high-pressure  port.  In  the  non-circulating  valve  the 
action  is  the  reverse  of  this.  At  all  times  the  low-pressure  water  has 
free  access  to  the  entire  valve  chamber,  through  the  central  opening  in 
the  high-pressure  valve  V  V ,  the  arrows  a  a  indicating  the  path  of  the 
stream.  In  starting  the  elevator  on  the  up  trip  the  valve  is  depressed 
until  the  top  of  the  lower  valve  V  uncovers  the  lower  port  in  the  valve 
chamber,  then  water  can  flow  into  the  upper  end  of  the  cylinder  and 
the  piston  will  be  depressed.  If  it  becomes  necessary  to  use  some  of 
the  high-pressure  water,  the  valve  is  further  depressed,  until  the  upper 
end  of  the  valve  V  V  uncovers  the  upper  part  of  the  high-pressure  port 
in  the  valve  chamber,  then  high-pressure  water  will  flow  in  and  passing 
down  through  the  valve  V  V  will  go  into  the  cylinder  together  with  the 
low-pressure  water. 

The  non-circulating  valve  is  not  used  very  extensively,  as  it  is 
required  only  in  cases  where  the  weight  of  the  lifting  ropes  is  compen- 
sated for  by  means  of  a  stand-pipe.  This  arrangement  is  far  more 
elegant  than  compensating  chains  dangling  in  the  elevator  well  from  the 
bottom  of  the  car,  but  is  considerably  more  expensive,  and  that  in  all 
probability  fully  accounts  for  its  not  being  more  generally  adopted.  In 
New  York  this  arrangement  is  in  use  in  the  St.  Paul  building  and  one  or 
two  others. 


CHAPTER  XIV 
OTIS  RUNNING-ROPE  SYSTEM 

The  rope  connections,  shown  in  Fig.  60,  for  operating  the  pilot  valve 
by  means  of  the  car  lever  L,  represent  one  form  of  the  running-rope 
system.  The  standard  running-rope  arrangement  used  by  the  Otis 
Elevator  Company  is  shown  in  Fig.  63.  The  horizontal  rock-lever  L'  is 
fastened  to  the  same  shaft  as  the  lever  L,  and  to  its  ends  are  secured  the 
running  ropes  n  ri.  The  upper  ends  of  these  ropes  are  made  fast  at  the 
upper  end  of  the  elevator  car,  as  shown  at  M  M'.  The  n  rope  passes 
under  a  sheave  a,  attached  to  the  side  of  sheave  C,  and  then  runs  up 
the  elevator  well  to  the  top  of  the  building  and  passes  over  the  sheave  a', 
thence  running  down  to  the  hitching  point  in  on  the  car  top.  The  n' 
rope  passes  under  the  sheave  b  attached  to  the  side  of  sheave  C,  opposite 
to  that  on  which  the  sheave  a  is  mounted,  and  thence  running  up  to  the 
top  of  the  building  passes  over  the  sheave  b'  and  down  to  the  top  of  the 
car  to  mf.  If  the  lever  L  is  moved  in  either  direction  it  will  lift  one  of 
the  ropes  and  depress  the  other,  and  thereby  cause  the  sheaves  a  and  b 
to  rotate  and  carry  with  them  the  sheave  C.  The  movement  of  the 
latter  sheave,  through  the  rope  C,  turns  the  actuating  sheave  i  on  the 
pilot  valve  stand. 

This  rigging  of  the  ropes  is  not  quite  the  same  as  that  shown  in 
Fig.  60,  as  the  latter  is  arranged  so  that  both  ends  of  each  running  rope 
are  attached  to  the  ends  of  the  rocking  lever.  Owing  to  this  difference 
the  ropes  in  passing  up  the  elevator  well  have  to  cross  over,  so  that  the 
one  that  passes  under  the  sheave  on  the  right  side  at  the  bottom  must 
pass  over  the  left  side  sheave  at  the  top.  This  way  of  arranging  the 
ropes  is  clearly  illustrated  in  the  diagram  Fig.  64,  in  which  the  solid 
lines  show  the  position  of  the  ropes  when  the  car  lever  is  in  the  central 
position,  and  the  broken  lines  represent  the  position  of  the  ropes,  and 
lower  sheaves,  when  L  is  shifted  to  the  position  A'.  An  examination 
of  this  diagram  will  show  clearly  why  it  is  necessary  to  cross  the  ropes 
in  the  elevator  well  when  all  the  ends  are  connected  with  the  rocking 
lever  L',  and  why  they  should  not  be  crossed  when  the  top  ends  are 
connected  to  the  upper  part  of  the  car  frame,  as  in  Fig.  63.  It  will  also 
be  seen  that  in  the  arrangement  of  Fig.  64,  if  the  operating  lever  is 

85 


86 


HYDRAULIC  ELEVATORS 


shifted  to  the  position  A,  points  a  and  b  will  be  shifted  to  a'  and  bf,  and 
the  lower  sheaves  c  and  d  will  be  shifted  to  c'  and  d' ;  that  is,  these 


FIG.  63  FIG.  64 

sheaves  will  be  moved  through  distances  equal  to  the  movement  of  the 
ends  of  the  rocking  lever,  or  in  other  words  through  a  distance  equal  to 
a  a'.  In  the  arrangement  of  Fig.  ,63,  however,  the  movement  of  the 


OTIS  RUNNING-ROPE  SYSTEM  87 

lower  sheaves  is  equal  to  one-half  the  distance  through  which  the  ends 
of  the  rocking  lever  are  moved.  In  both  cases  it  must  be  understood 
that  the  upper  sheaves  a'  and  b'  are  stationary. 

A    PUZZLING    PILOT   VALVE. 

The  pilot  valve  shown  in  Fig.  60  has  puzzled  quite  a  number  of 
engineers,  for  the  reason  that  the  valve  chamber  has  an  outlet  which  is 
generally  plugged  up,  and  the  object  of  this  outlet  is  not  easy  to  trace. 
The  construction  of  the  valve,  the  position  of  the  outlet,  and  its  object 
can  be  made  clear  by  the  aid  of  Fig.  65,  which  shows  on  the  left  side  a 
vertical  sectional  elevation  of  the  valve  chamber  with  the  valve  in  the 


FIG.  65 

stop  position,  and  on  the  right  side  another  vertical  section  of  the  chamber 
taken  at  right  angles  to  the  first-named,  while  at  the  top  a  plan  view  is 
given  showing  the  relative  position  of  the  three  outlets  of  the  chamber. 
The  outlet  that  will  almost  invariably  be  found  plugged  up  is  at  D. 
This  opening  was  originally  made  for  the  purpose  of  connecting  a 
pressure-regulating  device  intended  to  make  the  double-power  system 
automatic  in  action,  in  so  far  as  the  use  of  high-pressure  water  is  con- 


88  HYDRAULIC  ELEVATORS 

cerned.  When  this  device  is  used,  D  is  connected  with  the  upper  end 
of  the  valve  chamber,  and  in  the  pipe  connection  there  is  a  valve  that  is 
normally  closed,  but  is  controlled  by  a  pressure  regulator  that  in  turn 
is  connected  with  the  upper  end  of  the  cylinder,  and  is,  therefore, 
actuated  by  the  pressure  therein.  The  regulator  is  adjusted  so  as  to  act 
with  a  pressure  considerably  above  the  low-pressure  water.  The  opera- 
tion is  as  follows:  If  the  pressure  at  the  top  of  the  cylinder,  which  is 
due  to  the  load  in  the  car,  is  more  than  can  be  maintained  by  the  low- 
pressure  water,  flowing  in  at  the  required  velocity,  and  is  also  great 
enough  to  actuate  the  pressure  regulator,  so  as  to  open  the  valve  in  the 
pipe  connection  from  D  to  the  upper  end  of  the  valve  chamber,  then 
water  will  escape  from  the  upper  side  of  the  motor  piston  V ,  through 
this  D  connection,  and  thus  permit  the  valve  to  rise  higher  and  open  the 
high-pressure  valve  wider,  so  as  to  let  in  more  high-pressure  water,  and 
thus  increase  the  car  speed.  In  practice  it  has  been  found  that  this 
regulator  is  not  as  much  of  an  improvement  as  might  be  expected,  and 
if  it  gets  out  of  adjustment  slightly  is  liable  to  make  the  operation  of 
the  car  far  from  satisfactory.  If  it  is  set  to  act  at  a,  pressure  only 
slightly  above  the  low-pressure  water,  it  is  liable  to  set  the  car  in  opera- 
tion if  an  unusually  heavy  load  is  taken  on.  In  the  regular  running  of 
the  car,  also,  it  is  liable  to  produce  an  irregular  motion,  like  an  over- 
sensitive engine  governor.  For  these  reasons  it  has  been  practically  dis- 
carded, and  the  opening  D  plugged  up. 


CHAPTER  XV 

PRINCIPAL    CAUSES    OF    DISORDERED    MECHANISM    AND 

HOW    PREVENTED    OR    REMOVED— DIRECTIONS 

FOR  PACKING  THE  PISTONS  AND 

VALVES 

The  hydraulic  elevator,  like  every  other  type  of  machine,  must  be 
kept  in  perfect  order  to  give  satisfactory  results.  Some  of  the  effects 
produced  by  a  disordered  condition  of  the  mechanism  can  be  easily 
detected;  in  fact,  they  make  themselves  conspicuous  by  causing  the 
elevator  car  to  run  erratically.  Other  defects,  however,  can  be  discov- 
ered only  by  careful  inspection  of  the  entire  apparatus.  Disorders  of 
the  first-named  kind  do  not  as  a  rule  produce  any  permanent  injury  or 
deterioration  of  the  running  parts,  and  are  of  necessity  soon  rectified ; 
hence,  they  are  not  as  serious  as  those  of  the  second  type,  whose  only 
effect  is  to  deteriorate  the  apparatus.  The  principal  disorders  which 
produce  noticeable  effects  are  leaks  in  the  lifting-cylinder  piston,  the 
stuffing-boxes  and  the  valves.  These  cause  the  car  to  settle  slowly  after 
being  stopped. 

Sometimes  the  car  bounces  up  and  down  a  number  of  times  when 
stopping,  especially  if  a  sudden  stop  is  made.  This  action,  however,  is 
not  produced  by  an  actual  defect  in  any  part  of  the  apparatus  as  a 
general  rule,  but  is  moire  likely  due  to  an  accumulation  of  air  in  the 
lifting  cylinder.  This  air,  being  elastic,  will  compress  in  the  act  of 
stopping,  on  a  downward  trip  of  the  car,  and  will  expand  on  an  upward 
trip,  owing  to  the  fact  that  the  momentum  of  the  car  and  other  moving 
parts  resists  the  stopping,  thus  increasing  the  pressure  within  the  cylinder 
on  the  downward  trip  and  reducing  it  on  the  upward  trip.  After  the 
valve  has  been  closed  the  momentum  of  the  moving  parts  is  fully  absorbed 
either  by  compressing  the  air  to  a  pressure  greater  than  is  necessary  to 
balance  the  load,  or  by  expanding  it  to  a  lower  pressure.  As  a  result,  in 
the  first  case  the  extra  pressure  of  the  air  will  force  the  piston  down 
and  lift  the  car,  while  in  the  second  case  the  piston  will  move  upward 
to  compress  the  air  to  the  balancing  point,  and  .the  car  will  run  down. 

Owing  to  the  elasticity  of  the  air,  the  expansion  and  compression  will 
be  repeated  several  times,  imparting  to  the  car  a  teetering  motion  which 
is  supposed  by  many  people  to  be  produced  by  the  stretching  and  con- 

89 


90  HYDRAULIC  ELEVATORS 

trading  of  the  lifting  ropes.  As  this  teeter  effect  is  far  more  noticeable 
in  high  buildings,  the  belief  that  it  is  due  to  the  elasticity  of  the  ropes  is 
strengthened;  but  as  a  matter  of  fact  the  explanation  is  that  in  high 
buildings  the  car  speed  is  much  greater;  therefore,  the  stops  are  neces- 
sarily more  sudden,  and  the  momentum  of  the  moving  parts  produces  a 
greater  expansion  or  compression  of  the  air  confined  in  the  cylinder. 

Theoretically,  stretching  of  the  lifting  ropes  actually  takes  place  every 
time  the  car  is  stopped,  but,  although  ropes  when  very  lightly  loaded  will 
elongate  considerably  with  a  slight  increase  in  weight,  when  strained  to 
even  5  or  6  per  cent,  of  their  ultimate  strength  they  will  not  stretch 
much  more  than  solid  rods,  so  that  the  rise  and  fall  of  a  car  due  to  the 
stretching  of  the  ropes  is  probably  not  more  than  a  small  fraction  of  an 
inch,  even  for  a  length  of  two  hundred  feet  or  more. 

The  accumulation  of  air  in  the  lifting  cylinder  is  not  due  to  a  disor- 
dered condition  of  the  apparatus,  but  to  some  extent  it  may  be  excessive 
on  account  of  improper  arrangement  or  proportions  of  the  discharge  and 
pressure  tanks.  All  water  contains  air  in  very  small  bubbles,  the  amount 
being  greater  when  the  water  is  agitated  than  when  it  is  at  rest.  If  the 
pressure  is  increased  the  bubbles  come  together  and  form  a  smaller 
number  of  larger  size,  with  increased  buoyancy,  and  so  the  air  is 
"squeezed"  out  of  the  water.  If  the  water  is  compressed  into  a  tank 
where  it  can  remain  quiet  for  a  time,  considerable  air  will  be  forced 
out  of  it.  It  therefore  follows  that  with  a  large  pressure  tank  less  air 
will  pass  into  the  cylinder  than  with  a  small  one,  but  the  difference  is 
hardly  enough  to  warrant  the  use  of  an  extra  large  tank  for  this  reason 
alone,  and  it  is  seldom  taken  into  account  by  designers  of  elevator 
installations. 

In  some  cases  the  discharge  tank  may  be  so  arranged  as  to  cause  an 
undue  amount  of  air  to  get  into  the  water,  and  if  so  it  can  be  easily 
improved.  If  the  discharge  pipe  is  above  the  surface  of  the  water  in 
the  tank,  the  stream  falling  into  the  tank  will  carry  with  it  considerable 
air,  and  if  the  suction  pipe  is  nearby,  some  of  this  air  will  be  drawn 
into  the  pump.  By  placing  a  few  division  boards  within  the  tank  so 
as  to  space  off  the  suction  outlet,  the  water  will  have  a  chance  to  settle 
and  free  itself  of  most  of  the  air  before  it  is  drawn  into  the  pump. 

TO   REMOVE    AIR    FROM    LIFTING    CYLINDER. 

To  remove  air  from  the  lifting  cylinder,  when  the  air  has  accumulated 
in  sufficient  quantity  to  cause  the  car  to  teeter  noticeably  when  stopping, 
an  air-cock  is  provided  at  the  upper  end.  If  this  cock  is  left  open  while 
the  elevator  is  running,  all  the  air  will  be  expelled  after  a  few  trips 
have  been  made.  Most  of  the  air,  however,  is  forced  out  while  the  car 


DIRECTIONS  FOR  PACKING  THE  PISTONS  AND  VALVES 


91 


is  running  down.  On  the  up  trip  of  the  car,  water  rushes  into  the 
upper  end  of  the  cylinder  from  the  circulating  pipe,  and  the  surface  of 
the  water  is  kept  well  churned,  so  that  water,  as  well  as  air,  passes  out 
through  the  air-cock;  but  on  the  down  trip  the  piston  moves  upward, 
forces  the  water  up  against  the  air,  and  out  into  the  circulating  pipe. 
As  the  water  surface  remains  comparatively  quiet,  air  alone  passes 
through  the  cock,  and  a  far  greater  amount  is  expelled  than  in  the 
other  case.  When  all  the  air  is  out  of  the  cylinder,  the  bouncing  of 
the  car  will  stop,  and  then  the  air-cock  should  be  closed.  The  car  would 
continue  to  run  satisfactorily  with  the  cock  open,  but  there  would  be  an 


FIG.  66 


FIG.  67 


unnecessary  waste  of  water,  and  the  car  would  settle  after  stopping  at  a 
floor ;  hence,  it  is  important  to  make  sure  that  the  cock  is  closed. 

SETTLING   OF    THE    CAR. 

Whenever  the  elevator  car  settles  after  stopping  at  a  landing  it  is 
because  there  is  a  leak  in  either  the  piston  or  the  valves.  To  determine 
where  the  leak  is  located,  stop  with  the  car  above  the  lower  floor,  close 
the  gate  valve  in  the  supply  pipe,  and  move  the  main  valve  into  position 
for  the  upward  trip.  If  the  car  still  settles,  the  chances  are  that  the  leak 
is  in  the  piston,  because  the  packings  of  the  main  valve  will  be  above 
the  port  connecting  with  the  lower  end  of  the  cylinder,  and  to  circulate 
through  the  valve  the  water  would  have  to  pass  by  both  packings.  It  is 


92  HYDRAULIC  ELEVATORS 

improbable  that  both  packings  would  leak  at  the  same  time.  While  this 
is  not  a  positive  test,  it  is  the  best  available,  and  four  times  in  five  will 
prove  reliable. 

If  it  becomes  necessary  to  tighten  the  piston  packing,  the  way  to  do 
it  will  depend  upon  the  type  of  packing  and  piston.  Some  pistons  are 
designed  to  use  a  combination  packing,  consisting  of  a  deep  leather  cup 
with  an  outside  wearing  surface  of  square-section  rubber  rings.  The 
water  presses  the  leather  cup  against  the  rubber,  making  a  water-tight 
joint,  at  the  same  time  forcing  the  rubber  rings  against  the  cylinder 
surface.  The  construction  of  this  packing  will  be  understood  from 
Fig.  66.  This  style  of  packing  was  formerly  used  almost  exclusively 
and  is  to  be  found  in  nearly  all  the  elevators  which  were  installed 
fifteen  or  more  years  ago. 

In  modern  elevators  the  packing  used  for  pistons  is  the  same  as  that 
employed  for  steam-engine  piston-rod  stuffing-boxes,  and  the  piston  is 
made  with  a  packing  space,  and  a  compressing  ring  to  press  the  packing 
into  it.  The  construction  can  be  readily  understood  from  Fig.  67,  which 
shows  one  of  the  latest  designs  of  pistons  for  Otis  low-pressure,  vertical 
elevators,  although  in  this  design  the  piston  is  packed  from  the  upper 
side,  while  in  the  design  most  generally  used  it  is  packed  from  the 
under  side.  These  pistons  being  provided  with  regulation  stuffing-boxes, 
ordinary  hemp  packing  can  be  used,  but  unless  the  packing  is  done  with 
good  judgment  the  results  may  be  serious.  This  is  true  with  regard  to 
almost  any  kind  of  packing,  but  particularly  with  those  that  are  apt  to 
swell  appreciably  when  they  become  wet.  If  the  stuffing-box  is  packed 
very  tightly  with  a  dry  packing,  when  it  begins  to  absorb  water  it  will 
begin  to  swell,  and  may  continue  to  swell  until  it  bursts  the  cylinder. 

The  bursting  of  hydraulic-elevator  cylinders  is  not  an  unusual  thing, 
and  in  the  great  majority  of  cases  it  is  due  wholly  to  excessively  tight 
packing;  there  are  elevator  engineers  who  insist  that  this  is  always  the 
causa  Even  if  the  packing  is  not  tight  enough  to  burst  the  cylinder,  it 
may  be  tight  enough  to  absorb  so  much  of  the  power  of  the  water  as  to 
cause  the  car  to  run  much  too  slowly,  not  to  speak  of  the  waste  of  power. 

PACKING   THE  PISTON. 

If  the  piston  is  made  so  as  to  be  packed  from  the  upper  end  of  the 
cylinder,  the  course  of  procedure  in  packing  is  as  follows:  The  car  is 
run  to  the  bottom  of  the  elevator  well;  then  the  valve  in  the  supply  pipe 
is  closed,  to  prevent  water  from  flowing  in  from  the  pressure  tank  while 
the  packing  is  being  done.  The  next  step  is  to  remove  the  water  in  the 
cylinder  above  the  piston,  and  this  is  accomplished  by  opening  the  air- 
cock  in  the  upper  cylinder-head,  and  also  a  valve  that  connects  the  drain 


DIRECTIONS  FOR  PACKING  THE  PISTONS  AND  VALVES  93 

pipe  with  a  point  on  the  side  of  the  cylinder  below  the  bottom  of  the 
piston,  when  the  water  will  be  drawn  off  into  the  drain  pipe.  After  this 
much  is  accomplished,  the  cylinder-head  is  to  be  removed,  but  before 
doing  this  the  position  of  the  part  which  contains  the  piston-rod  stuffing- 
boxes  and  the  location  of  the  outer  clamping  ring  must  be  carefully 
marked,  so  that  when  the  head  is  replaced  the  parts  may  be  returned 
to  their  original  positions. 

It  must  be  borne  in  mind  that  in  removing  the  old  and  putting  in  the 
new  packing,  it  is  possible  to  impart  to  it  a  rotary  movement  that  would 
throw  the  piston-rods  out  of  line.  When  the  cylinder-head  has  been 
removed,  the  stuffing-box  gland-screws  are  removed,  and  the  gland  is 
raised  out  of  the  way;  then  the  old  stuffing  is  taken  out  and  new  put  in, 
as  in  any  other  stuffing-box.  It  is  to  be  observed,  however,  that  as  it  is 
a  far  more  laborious  job  to  pack  an  hydraulic  piston  than  a  steam-engine 
or  pump  stuffing-box,  greater  care  should  be  taken  to  make  sure  of  not 
having  to  open  up  the  cylinder  a  second  time. 

As  before  stated,  not  only  is  there  danger  of  bursting  the  cylinder  if 
the  packing  is  pressed  in  too  tightly,  but  even  if  this  damage  does  not 
result,  there  will  be  excessive  friction ;  therefore,  every  care  must  be 
taken  not  to  get  the  packing  too  tight.  At  the  same  time  it  is  necessary 
that  it  be  tight  enough  to  prevent  the  water  from  passing,  and,  while  it  is 
not  possible  to  give  specific  directions  or  signs  by  which  to  determine 
when  the  packing  is  tight  enough,  men  of  experience  will  have  no 
difficulty  in  determining  this  point. 

To  avoid  trouble  in  replacing  the  packing-gland,  it  is  advisable  to 
mark  the  position  in  which  it  goes  before  removing  it,  so  as  to  replace 
it  in  the  same  position.  As  it  is  necessary  that  the  gland  be  screwed 
down  evenly  all  around,  that  is,  so  that  its  outer  surface  may  be  parallel 
with  the  cylinder,  the  distance  from  its  upper  surface  to  the  top  of  the 
cylinder  should  be  accurately  measured  at  four  points  equidistant  from 
each  other. 

If,  when  the  cylinder-head  is  removed,  it  be  found  that  the  piston  is 
too  far  down  to  be  reached  conveniently,  it  can  be  raised  by  placing  a 
clamp  on  the  lifting  ropes  some  distance  above  the  car  and  drawing  it 
down  by  means  of  a  tackle  attached  to  the  upper  frame  of  the  car.  In 
doing  this  care  must  be  taken  that  the  clamp  is  attached  only  to  the 
lifting  ropes,  and  not  to  those  that  run  to  the  independent  counter- 
balance. In  cases  where  the  machine  is  geared  high — four  or  six  to  one — 
and  the  independent  counterbalance  is  light,  this  method  may  not  prove 
satisfactory,  unless  the  car  is  loaded  so  that  it  cannot  be  lifted  by  this 
effort  to  raise  the  piston.  The  piston  can  also  be  raised  directly  by 
pulling  up  the  traveling-sheave  frame;  but  if  this  is  done  it  will  be 


94  HYDRAULIC  ELEVATORS 

necessary  to  be  careful  to  return  the  ropes  to  their  proper  position  when 
the  frame  is  lowered,  and  in  some  cases  this  is  not  easily  done  on  account 
of  the  sheaves  not  being  in  a  position  where. the  ropes  can  be  readily 
reached.  If  the  piston  is  raised  so  high  as  to  bring  the  packing  opposite 
the  porthole  connecting  with  the  circulating  pipe,  care  must  be  taken 
that  in  lowering  it  the  packing  is  not  caught,  also  that  the  packing  is  not 
forced  out  into  the  port  while  placing  it  in  the  stuffing-box. 

After  the  piston  is  packed  and  the  cylinder-head  is  replaced,  one 
should  see  that  the  air-cock  is  open,  and  that  the  main  valve  is  in  the 
stop  position.  Then  slowly  open  the  valve  in  the  supply  pipe,  and  keep 
the  air-cock  open  until  water  runs  out  of  it,  indicating  that  all  the  air 
is  expelled ;  then  close  the  air-cock  and  the  elevator  will  be  ready  to  run. 

If  the  piston  packing  is  of  the  leather-cup  and  rubber-ring  type,  the 
packing  process  is  the  same  as  described,  with  the  exception  that  after 
removing  the  follower  F,  Fig.  66,  the  next  step  is  to  remove  the  leather 
cup  and  clean  out  thoroughly  the  packing  space,  and  also  the  holes  in 
the  follower  through  which  the  water  passes  to  press  out  the  leather 
cup.  If  the  cup  is  found  to  be  in  good  condition,  which  is  probable,  it 
may  be  used  again,  but  if  much  worn  it  must  be  replaced,  and  to  get 
the  new  one  in  position  it  will  be  necessary  to  cut  it  carefully  on  a 
diagonal  line,  so  as  to  pass  it  over  the  piston-rods ;  then  it  must  be  sewn 
up  neatly  (which  is  not  an  easy  job),  so  that  it  may  be  of  the  same  shape 
and  size  as  before  cutting.  The  rubber  rings  are  to  be  replaced  by 
others  of  the  same  size;  the  cross-section  is  generally  y%  inch  square. 
They  should  be  cut  somewhat  longer  than  the  circumference  of  the  circle, 
say  from  Y^  to  J^  inch,  according  to  the  diameter  of  the  cylinder,  so 
that  the  ends  may  be  pressed  tightly  against  each  other.  Three  rings 
are  usually  required,  and  they  should  be  of  such  thickness  as  not  to  fill 
up  the  space  tightly,  for  if  they  do  they  may  not  be  forced  out  against 
the  cylinder  wall  by  the  leather  cup.  If  they  fit  loosely  they  will  be 
pressed  out  so  as  to  make  a  tight  fit. 

If  the  piston  must  be  packed  from  the  bottom,  the  packing  operation 
is  the  same  as  that  just  described,  but  the  piston  must  be  run  down  to 
the  lower  end  of  the  cylinder,  which  means  that  the  car  must  be  run  to 
the  top  of  the  building.  In  order  that  the  piston  may  be  brought  low 
enough  to  be  easily  reached,  it  must  be  run  down  until  it  strikes  the 
lower  cylinder-head,  and  to  do  this  in  the  case  of  a  hand-rope-operated 
elevator  it  is  necessary  to  slide  up  the  stop-ball  on  the  hand  rope.  In  the 
case  of  a  pilot-valve  machine,  the  stop-ball  on  the  rope  that  actuates 
the  automatic  stop-valve  must  be  moved.  In  either  case,  the  car  is  first 
run  up  as  far  as  it  will  go,  then  the  stop-ball  is  shifted  to  a  point  where 
it  will  prevent  the  car  from  moving  far  enough  to  get  up  a  speed  that 


DIRECTIONS  FOR  PACKING  THE  PISTONS  AND  VALVES 


95 


would  cause  the  piston  to  strike  the  cylinder-head  hard,  even  if  it  were 
not  run  up  carefully.  In  running  up  the  car,  however,  the  valve  should 
be  opened  just  enough  to  cause  the  car  to  move. 

When  the  car  is  run  up  until  the  piston  rests  on  the  lower  cylinder- 
head,  it  must  be  secured  to  the  overhead  beams  by  means  of  ropes  several 
times  as  strong  as  may  be  considered  necessary  to  hold  it  safely,  say  ten 
times  as  strong.  This  being  done,  the  valve  in  the  supply  pipe  is  closed, 


FIG.  68 


FIG.  69 


and  the  car  lever  is  turned  for  the  down  trip,  so  as  to  connect  the 
circulating  pipe  with  the  lower  end  of  the  cylinder.  The  next  step  is  to 
open  the  valves  connecting  the  drain  pipe  with  the  side  and  bottom  of 
the  cylinder,  and  also  the  air-cock  at  the  top,  so  as  to  drain  out  the 
water.  If  the  discharge  tank  is  higher  than  the  bottom  of  the  cylinder, 
the  valve  in  it  must  be  closed,  so  that  the  tank  water  may  not  run  into 
the  cylinder,  as  it  would  otherwise  surely  do,  owing  to  the  fact  that  the 
cup  packings  in  the  valve  are  not  set  so  as  to  be  tight  against  water 


96  HYDRAULIC  ELEVATORS 

running  in  from  the  discharge  end  of  the  valve  cylinder.  Having  drained 
the  cylinder,  the  lower  head  is  removed  and  the  packing  is  done  in  the 
same  manner  as  for  top-packed  pistons. 

In  the  latest  designs  of  bottom-packed  pistons,  one  of  which  is  shown 
in  Fig.  68,  the  packing  chamber  is  made  deep  and  the  clamping  ring  R  is 
screwed  tightly  against  the  bottom  of  the  piston.  This  renders  it  unnec- 
essary to  measure  the  distance  from  the  ring  to  the  lower  end  of  the 
cylinder  to  make  sure  that  it  is  in  its  true  position,  because  when  screwed 
up  tightly  it  will  be  true;  but  as  there  is  no  provision  for  adjusting  the 
depth  of  the  packing,  the  latter  must  be  gaged  in  quantity  so  that  it  will 
be  just  tight  enough  when  the  clamping  ring  is  screwed  up.  Owing  to 
the  greater  amount  of  packing  there  is  no  difficulty  in  doing  this,  gen- 
erally, without  splitting  any  of  the  packing.  When  the  piston  is  repacked, 
and  the  cylinder-head  in  place,  move  the  main  valve  to  the  up-trip 
position,  so  as  to  just  open,  then  open  slightly  the  valve  in  the  supply 
pipe,  having  first  closed  the  valves  connecting  with  the  drain  pipe.  Leave 
the  air-cock  open  and  the  cylinder  will  fill  slowly  with  water,  and  the 
air  will  be  expelled.  When  all  the  air  is  out,  close  the  air-cock  and 
return  the  main  valve  to  the  stop  position;  then  open  the  supply-pipe 
valve  wide,  release  the  car  and  run  it  down  a  short  distance ;  then  reset 
the  stop-ball,  and  the  elevator  will  be  ready  to  run. 

The  piston-rods  pass  through  stuffing-boxes  of  the  same  type  as  those 
used  on  steam  engines,  as  can  be  seen  from  Fig.  69,  and  they  are  packed 
in  the  same  way.  To  keep  the  glands  from  working  loose  the  locking 
piece  29  is  provided,  and  this  is  secured  in  place  by  the  stud  28.  In 
repacking  the  piston-rod  boxes,  one  should  always  be  sure  to  replace 
the  lock-clamp  29,  especially  if  the  cylinder  is  located  in  the  elevator 
well  at  one  side  of  the  car,  because  if  the  cap  of  one  of  the  boxes  should 
work  loose,  it  might  permit  the  water  to  spray  out  in  sufficient  quantity 
to  give  the  passengers  in  the  car  an  undesirable  shower  bath.  Before 
starting  to  pack  the  piston-rods,  the  car  should  be  run  to  the  bottom  of 
the  building  and  the  valve  in  the  supply  pipe  closed,  so  as  to  remove 
the  pressure  in  the  cylinder,  and  thus  prevent  water  from  spurting  out 
of  the  stuffing-box.  It  is  also  advisable  to  open  the  air-cock  so  as  to  be 
sure  of  relieving  the  pressure  entirely.  Flax  packing  is  recommended 
for  this  service,  and  it  should  be  about  *4  inch  in  diameter.  About  eight 
turns  will  be  sufficient. 

TO   PACK   THE  VALVES. 

To  pack  the  valves  they  must  be  removed  from  the  valve  chamber,  so 
they  may  be  taken  apart  to  remove  the  old  cups  and  put  new  ones  in 
their  places.  There  is  no  difficulty  in  removing  the  valves  from  machines 


DIRECTIONS  FOR  PACKING  THE  PISTONS  AND  VALVES 


97 


provided  with  a  pilot- valve  gear  without  a  throttling  valve,  •  as  there  is 
nothing  to  interfere  with  the  free  withdrawal  of  the  leather  cups.  This 
may  be  seen  at  once  from  Fig.  53,  which  is  a  vertical  section  of  such  a 
valve.  It  will  be  evident  that  both  the  small  lower  chamber  and  the 
large  upper  one  are  smooth,  so  that  as  soon  as  the  valve-chamber  head 
is  removed  and  the  connecting-rod  is  free,  the  valve  can  be  drawn 
upward.  In  Fig.  29,  wrhich  is  a  vertical  section  of  a  simple  valve  of  the 
type  used  with  hand-rope  control,  the  cups  of  the  lower  valve  have  to 
pass  over  the  space  12,  and  thus  are  liable  to  catch  on  the  upper  lining  4. 
This  difficulty  seldom  occurs,  however,  because  the  inner  edge  of  the 
lining  is  rounded  off,  in  the  manner  illustrated  in  Fig.  70,  so  that  the  cup 


FIG.   70 


FIG.  71 


can  spread  out  considerably  before  it  will  be  caught,  as  indicated  by  the 
dotted  line  a. 

These  valves  are  not  all  made  in  this  way.  In  many  of  them  the  lin- 
ings j  and  4  are  combined  in  one,  with  ports  cut  through  where  the  space 
12  comes,  the  construction  being  as  illustrated  in  Fig.  71.  If  the  valve 
chamber  is  constructed  as  in  Fig.  29,  and  the  cup  appears  to  catch,  it  can 
usually  be  freed  by  gently  rotating  the  valve,  at  the  same  time  pulling 
it  up  just  hard  enough  to  make  it  lift  if  the  cup  slides  back  into  position. 
If  this  method  fails  to  free  the  cup,  then  the  proper  thing  to  do  is  to 
drop  the  valve  back  far  enough  for  the  cup  to  enter  the  lining  j,  and 


98  HYDRAULIC  ELEVATORS 

allow  the  valve  to  remain  in  this  position  for  a  few  minutes,  so  as  to 
allow  the  leather  to  set,  and  then  try  to  lift  the  valve  again,  but  with 
greater  care. 

Differential  valves  provided  with  a  throttle  generally  work  in  cham- 
bers constructed  as  shown  in  Fig.  71,  and  with  these  there  is  no  difficulty 
in  removing  the  valve,  because  if  the  packings  spread  out  and  catch  they 
can  be  pressed  back  by  simply  rotating  the  valve,  as  the  longitudinal 
connecting  bars  a  will  flatten  down  the  raised  edge  of  the  cup. 

To  pack  the  main  valve  it  is  necessary  to  run  the  car  to  the  top  of 
the  building  and  secure  it  there,  the  same  as  for  packing  the  piston  from 
the  lower  end  of  the  cylinder,  the  only  difference  being  that  it  is  not 
necessary  to  lift  the  car  any  farther  than  it  ordinarily  runs.  After 
firmly  securing  the  car,  the  valve  in  the  supply  pipe  is  closed,  and  then 
the  water  is  drawn  off  the  circulating  pipe  by  opening  the  valve  that 
connects  its  lower  end  with  the  drain  pipe.  If  the  discharge  tank  is 
higher  than  the  bottom  of  the  valve  this  must  also  be  shut  off,  so  that 
the  water  may  not  run  out  of  the  tank  through  the  valve  chamber  when 
the  valve  is  removed. 

If  the  valve  is  of  the  rack  and  pinion  type  used  with  hand-rope 
control,  all  that  is  necessary  after  securing  the  car  and  closing  the  supply 
and  discharge  valves  is  to  remove  the  bolts  and  take  off  the  cap  and  the 
intermediate  block  which  contains  the  bearing  in  which  the  hand-rope 
sheave  rotates.  This  having  been  done,  the  valve  can  be  removed.  If 
the  valve  is  of  the  differential  type,  then  the  upper  end  of  the  valve-rod 
must  be  disconnected  from  the  cross  lever  that  connects  it  with  the  pilot 
valve,  and  the  pipe  connection  with  the  upper  head-  must  be  broken; 
then  the  head  can  be  lifted  off  and  the  valve  drawn  out. 

The  valves  should  be  packed  at  a  time  when  it  is  not  necessary  to 
hurry  in  getting  the  elevator  back  into  operation,  in  order  that  the  valves 
may  be  allowed  to  soak  for  an  hour  or  two  after  the  new  cups  have 
been  put  in  place.  To  make  sure  that  the  cups  are  tightly  clamped 
between  the  valve  body  and  the  head,  it  is  advisable  to  drop  a  little  oil 
on  the  flat  part  of  the  leather  before  putting  it  in  place,  so  as  to  soften  it. 
After  the  repacked  valve  has  been  replaced  and  the  valve  chamber 
properly  closed,  all  connections  having  been  correctly  made,  the  valves 
in  the  supply  and  discharge  pipes  must  be  opened,  also  the  air-cock  in  the 
top  of  the  cylinder,  so  as  to  fill  up  the  circulating  pipe  and  dispel  the  air 
from  the  upper  end  of  the  cylinder;  then  close  the  air-cock  and  the 
elevator  is  ready  to  run. 

To  replace  the  cup  packings  in  the  pilot  valve  it  is  necessary  to  close 
the  valve  in  the  supply  pipe,  after  running  the  car  to  the  bottom  of  the 
well.  If  the  discharge  tank  is  higher  than  the  valve,  the  discharge 


DIRECTIONS  FOR  PACKING  THE  PISTONS  AND  VALVES  99 

connection  must  also  be  closed.  The  valve,  as  may  be  understood  from 
Fig.  65,  can  be  drawn  put  of  the  chamber  as  soon  as  its  upper  end  is 
disconnected  from  the  connecting-rod.  The  cups  at  the  lower  end  of 
the  valve  will  have  to  pass  up  over  the  break  in  the  lining  at  B,  but  as 
the  inner  corners  are  rounded  off,  there  should  be  no  difficulty  in 
passing  this  point.  Before  removing  the  pilot  valve  it  is  advisable  to 
draw  just  enough  water  from  the  circulating  pipe  to  remove  the  pressure, 
in  order  that  none  may  spill  out  through  the  top  of  the  pilot-valve 
chamber.  If  the  large  valve  at  the  upper  end  of  the  main  valve,  which 
is  called  the  motor  piston,  is  not  tight,  the  pilot  valve  cannot  be  removed 
until  all  the  water  that  is  above  the  level  of  the  pilot-valve  chamber  is 
drawn  from  the  circulating  pipe ;  otherwise,  this  water  would  pass  by 
the  motor  piston  into  the  upper  end  of  the  main  valve  chamber,  and 
thence  through  the  pipe  connection  to  the  inlet  D  of  the  pilot  valve. 


CHAPTER  XVI 

AUTOMATIC  DEVICES  USED  FOR  STOPPING  CARS  AT  TOP 

AND  BOTTOM  LANDINGS;  THEIR  CARE  AND  THEIR 

VALUE  AS  SAFETY  APPLIANCES 

The  automatic  devices  employed  to  stop  elevator  cars  at  top  and 
bottom  landings  are  the  most  valuable  safety  appliances  used,  and  they 
must  be  kept  in  perfect  working  order.  For  systems  in  which  the  cars 
are  operated  by  the  ordinary  hand-rope  method,  the  automatic  stopping 
device  is  very  simple.  It  consists  of  two  stop-balls  fastened  to  the  hand 
rope  at  the  top  and  bottom  in  such  manner  that  they  will  be  caught  by 
the  sleeve  through  which  the  rope  slides,  a  little  before  the  car  reaches 
the  stopping  point.  These  stop-balls  are  so  adjusted  that  the  sleeve 
strikes  them  at  the  proper  distance  from  the  floor  level  to  cause  the  car 
to  come  to  a  state  of  rest  three  or  four  inches  beyond  the  floor,  if 
running  at  normal  speed.  As  the  careful  operator  usually  pulls  the 
hand  rope  to  stop,  the  stop-balls  are  not  often  struck  by  the  sleeve. 
When  the  car  is  stopped  properly  by  the  operator  the  reduction  in  speed 
is  more  gradual  than  would  be  the  case  if  the  stop-balls  were  relied  upon. 

Although  it  adds  to  the  comfort  of  the  passengers  not  to  have  the 
car  stopped  by  means  of  the  stop-balls,  it  makes  it  more  imperative  to 
examine  the  stop-balls  frequently  and  carefully  in  order  that  there  may 
be  as  little  danger  as  possible  of  their  getting  loose  and  shifting  out  of 
place.  If  the  car  were  frequently  stopped  by  the  stop-balls,  any  slight 
displacement  of  them  would  become  apparent  by  the  car  running  a  little 
beyond  the  point  where  it  should  stop,  indicating  that  the  stop-ball  had 
shifted.  By  taking  advantage  of  this  warning,  the  stop-ball  can  be 
returned  to  the  proper  position  before  serious  damage  results.  If,  how- 
ever, the  automatic  stop  is  rarely  used,  the  ball  may  become  loose  and 
shifted  out  of  position  a  distance  that  would  be  dangerous.  This  is 
especially  likely  to  occur  with  the  bottom  stop-ball,  as  gravity  will  cause 
it  to  slide  down  on  the  hand-rope  after  it  becomes  loose  and  it  will  not 
be  in  place  to  stop  the  car  when  needed.  With  the  upper  stop-ball  there 
is  not  so  much  danger,  because  if  it  slides  down  it  will  only  come  into 
action  too  soon,  and  stop  the  car  before  it  reaches  the  top  floor.  Yet  it 
is  possible  for  the  upper  stop-ball  to  become  just  loose  enough  to  be 

100 


AUTOMATIC  DEVICES  USED /FOR;  STOPFI-NP  ,CAP.S  ,  101 

pushed  up  on  the  rope  when  struck  by  the  sleeve,  and,  although  it  may 
not  slide  up  far  enough  to  permit  the  car  to  rise  too  high  at  the  time,  it 
will  in  all  probability  be  high  enough  to  fail  to  act  when  next  called 
upon;  therefore,  the  upper  stop-ball  requires  nearly  as  much  watching 
as  the  lower  one. 

STOP-VALVE  FOR   PILOT-VALVE  CONTROL. 

In  the  case  of  pilot-valve  elevators,  the  automatic  stopping  device  is 
entirely  separate  from -the  operating  lever  in  the  car,  and  is  actuated  by 
the  movement  of  the  cross-head  of  the  lifting  piston.  It  is  much  more 
complicated  than  the"  stop-ball  device,  as  it  comprises  a  number  of  parts, 
and  there  is  more  chance  for  it  to  get  out  of  order  if  neglected.  A 
description  of  the  automatic  stop-valve  and  connections  used  with  pilot- 
valve  control  is  given  in  Chapter  IX,  but  the  action  of  this  valve  and 
the  way  in  which  it  should  be  adjusted  will  be  more  fully  explained 
herewith,  in  connection  with  the  elevator  elevation  drawing,  Fig.  33.  It 
might  be  assumed  that  as  this  drawing  represents  only  one  design  of 
automatic  stop-valve  for  use  with  pilot-valve  control,  the  explanation 
will  be  of  service  only  in  connection  with  this  particular  machine,  but 
such  is  not  the  case;  all  hydraulic  elevators  provided  with  pilot-valve 
control  are  constructed  upon  the  same  principle,  being  different  only  in 
detail  modifications,  so  that  what  is  true  of  the  general  principles  of 
operation  for  one  is  true  of  all,  and  all  that  is  necessary  is  to  take  into 
account  the  changes  in  form  of  the  various  parts,  which  in  most  cases 
is  trifling. 

In  Fig.  33  the  automatic  stop- valve  is  located  at  B",  and  is  actuated 
by  the  rope  5,  which  runs  upward  by  the  side  of  the  hydraulic  cylinder 
to  a  point  several  feet  above  the  highest  position  reached  by  the  arm  / 
attached  to  the  crosshead  of  the  machine.  The  rope  5  passes  over  a 
sheave  at  the  upper  end,  as  clearly  shown  in  the  drawing,  and  down 
around  the  sheave  18,  which  is  mounted  in  a  bearing  attached  to  the 
chamber  of  the  automatic  valve  B". 

The  arrangement  and  location  of  the  sheave  18  can  be  better  under- 
stood from  Fig.  72.  On  the  shaft  of  18  there  is  a  pinion  that  meshes 
into  the  gear  77,  which  is  mounted  on  the  end  of  the  shaft  that  carries 
the  center  49  of  the  valve  B".  The  ratio  between  the  diameters  of  the 
gear  77  and  the  pinion  on  the  shaft  of  the  sheave  18  is  such  that  77 
makes  a  quarter  of  a  turn  between  the  instant  when  the  arm  7  strikes 
either  one  of  the  stop-balls  8  and  p  and  the  time  when  the  car  comes 
to  a  state  of  rest.  During  this  interval  the  flow  of  water  through  the 
valve  B"  is  reduced  so  gradually  as  to  bring  the  elevator  to  a  stop 
without  a  noticeable  jar  if  the  velocity  is  not  above  the  normal.  The 
weight  7p  provides  the  necessary  momentum  to  return  the  stop-valve  to 


IO2  HYDRAULIC  ELEVATORS 

A  Al  >  ,%  *  «  ? 

,V*    :   3»     i  /  '   S  •          *  .  *W  7    r  *  X    '  ,- 

the  open  position  when  the  main  valve  is  turned  so  as  to  move  the  car 
in  the  opposite  direction. 

In  Fig.  33  it  will  be  noticed  that  the  arm  7  acts  on  stop-balls  placed 
on  the  right-hand  rope,  therefore  if  the  elevator  is  going  upward,  as  7 
will  be  moving  downward,  the  ball  p  will  be  struck,  and  thus  the  sheave 
18  will  be  rotated  clockwise,  and  the  movement  of  17  and  the  valve  B" 
will  be  counter-clockwise ;  the  curved  plate  50,  Fig.  72,  will  swing  around 
to  the  right  side  and  cover  the  outlet  from  the  lower  end  of  the  cylinder 


FIG.   72 


to  the  main-valve  chamber,  stopping  the  motion  of  the  piston,  and,  con- 
sequently, the  car.  The  curved  piece  50  is  held  in  the  center  carrier  49 
loosely,  so  that,  while  the  pressure  of  the  water  trying  to  escape  from 
the  lower  end  of  the  cylinder  will  force  it  against  the  valve  seat,  to 
make  a  tight  joint,  if  the  main  valve  is  depressed  and  pressure  is  brought 
on  the  outside  of  50,  it  will  be  forced  away  from  the  seat,  and  water 
from  the  circulating  pipe  B  will  pass  through  the  small  opening  slowly 
and  produce  a  gradual  start  of  the  elevator. 

As  soon  as  the  piston  begins  to  move  upward  the  arm  7  will  also 
move,  when  gravity  will  draw  the  weight  19  downward  to  its  lowest 
position.  When  the  car  is  sufficiently  near  the  lower  floor  for  the 
automatic  stop-valve  to  act,  the  arm  7  will  strike  the  ball  8,  and  by 
pulling  up  the  right-hand  side  of  the  operating  rope  will  rotate  the 


AUTOMATIC  DEVICES  USED  FOR  STOPPING  CARS  103 

sheave  18  counter-clockwise,  swing  the  plate  50  around  to  the  left  and 
prevent  the  flow  of  water  into  the  lower  end  of  the  cylinder. 

Again,  it  will  be  seen  that  as  long  as  the  main  valve  is  depressed  the 
pressure  will  hold  50  against  the  seat,  and  prevent  the  escape  of  water 
from  the  lower  end  of  the  cylinder;  but  if  the  main  valve  is  now  raised, 
so  as  to  connect  the  port  from  the  valve  B"  with  the  discharge  pipe,  the 
pressure  against  the  inner  side  of  50  will  be  removed,  and  the  water  in 
the  lower  end  of  the  cylinder  will  force  50  away  from  its  seat  and  escape/ 
permitting  the  piston  to  move  downward  slowly.  As  the  piston  moves 
down,  the  arm  7  will  also  move  down  and  free  the  stop-ball  8,  so  that 
gravity  again  acting  on  ip  will  swing  it  down  to  the  central  position  and 
move  50  entirely  out  of  the  way  of  the  flowing  water. 

If  the  plate  50  were  not  held  loosely  in  the  carrier  49,  the  elevator 
could  not  be  started  after  it  had  reached  either  end  of  the  well,  because 
the  flow  of  water  would  be  effectually  stopped,  and  the  opening  of  the 
main  valve  for  either  direction  of  movement  would  not  have  any  effect. 
As  the  water  used  for  operating  elevators  is  generally  clean,  or  at  least 
free  from  bodies  large  and  strong  enough  to  wedge  the  plate  50  in  the 
closed  position,  there  is  very  little  danger  of  an  elevator  becoming  stalled 
through  this  cause.  If,  however,  the  car  should  refuse  to  start  from 
either  end,  and  no  other  reason  could  be  found  for  its  not  moving,  it 
could  be  inferred  that  the  plate  50  was  held  firmly  against  the  seat  in 
some  unexpected  manner.  Whether  such  were  the  case  could  be  easily 
ascertained  by  placing  the  main  valve  so  as  to  just  open  for  the  desired 
direction  of  movement,  and  then  move  the  stop-ball  away  from  the  arm  7 
to  allow  the  weight  19  to  drop  to  the  central  position.  Upon  doing  this, 
if  the  elevator  were  set  in  motion,  it  would  show  that  50  had  been 
caught,  and  then  the  valve  chamber  should  be  opened  to  ascertain  and 
remedy  the  cause. 

TO  REMEDY  DEFECTS   CAUSED  BY  FRICTION. 

While  it  is  improbable  that  anything  will  cause  the  plate  50  to  remain 
against  its  seat  when  the  main  valve  is  reversed,  it  is  possible  for  the 
weight  ip  to  be  incapable  of  overcoming  the  friction  of  all  the  moving 
parts  of  the  automatic  valve-gear,  and  when  the  main  valve  is  moved 
into  position  to  run  the  car  up  from  the  lower  landing,  or  down  from 
the  top,  the  weight  19  may  not  return  to  the  central  position,  but  remain 
at  the  side.  If  this  should  occur  it  would  prevent  the  car  from  attaining 
a  speed  anywhere  near  normal ;  in  fact,  it  would  not  run  with  much 
more  than  10  per  cent,  of  the  normal  velocity.  To  remedy  a  defect  of 
this  kind  it  is  necessary  to  find  out  where  the  valve  mechanism  sticks,  and 
put  it  in  proper  condition,  which  in  most  cases  can  be  done  by  thoroughly 


IO4  HYDRAULIC  ELEVATORS 

cleaning,  readjusting  and  oiling  all  the  bearings  and  relieving  any  undue 
friction  in  the  stuffing-boxes. 

The  refusal  of  the  automatic  stop-valve  to  return  to  the  open  position 
when  the  elevator  is  started  from  either  end,  due  to  the  sticking  of  the 
moving  parts,  is  not  the  most  serious  thing  that  can  occur  with  it. 
Suppose  the  valve  mechanism  works  so  hard  that  when  the  arm  7  strikes 
one  of  the  stop-balls  it  simply  slides  it  along  on  the  rope,  what  would 
be  the  result?  Simply  that  the  car  would  not  stop,  but  would  pass  the 
floor,  and  if  at  the  bottom  of  the  building  it  might  strike  the  bumpers 
hard  enough  to  injure  passengers,  unless  the  ropes  were  rather  short,  in 
which  case  the  piston  would  be  drawn  up  against  the  top  cylinder-head 
before  the  car  struck  and  damage  the  cylinder -head,  piston  or  other 
parts.  If  the  stop-ball  were  to  slip  when  the  car  was  running  upward, 
the  piston  would  strike  the  bottom  cylinder-head,  with  more  or  less 
serious  results.  From  the  foregoing  it  will  be  apparent  that  it  is  of  the 
utmost  importance  to  keep  the  automatic  stop-valve  mechanism  in  perfect 
condition  all  the  time,  the  bearings  and  gears  running  freely  and  well 
oiled,  and  the  stuffing-boxes  tight  enough  to  prevent  leakage,  but  not  too 
tight  to  prevent  the  valve-rod  from  revolving  freely.  The  stop-balls 
must  be  firmly  secured  in  position,  and  the  fastening  of  the  weight  ip 
must  be  perfect. 

To  secure  correct  running  of  the  elevator  the  valve  22  must  be  in 
good  order.  If  it  leaks,  the  car  will  settle  when  standing  at  a  landing, 
and  if  the  spring  22'  becomes  clogged  and  fails  to  compress  freely,  smooth 
stops  will  not  be  made  when  running  upward  or  when  the  car  is  stopped 
at  the  top  floor  by  the  automatic  valve,  if  the  car  is  running  at  high 
speed.  In  such  cases  it  generally  happens  that  the  operator  closes  the 
main  valve  too  abruptly,  and  the  automatic  valve  may  close  too  soon; 
but  if  the  valve  22  is  working  properly  the  excess  of  pressure  developed 
in  the  lower  end  of  the  cylinder  by  the  compressing  action  of  the  piston, 
due  to  its  momentum,  will  force  the  valve  up,  allow  the  water  to  escape 
from  the  lower  end  of  the  cylinder  into  the  circulating  pipe,  and  permit 
the  piston  to  move  down  some  distance  farther  before  coming  to  a  stop. 

The  reason  why  the  automatic  stop  is  the  most  valuable  of  all  elevator 
safety  devices  is  that  if  the  car  for  any  reason  runs  down  with  abnormally 
high  velocity,  and  all  the  usual  safety  appliances  fail  to 'act  and  stop  it 
before  it  reaches  a  point  near  the  lower  landing,  the  automatic  stop  will 
begin  to  act,  and  by  gradually  stopping  the  flow  of  water  will  arrest  the 
motion  of  the  car,  so  that  if  it  does  not  stop  before  reaching  the  bumpers 
its  velocity  will  have  been  reduced  and  a  disagreeable  jolt  will  be  the 
worst  result.  If  elevator  accidents  were  due  to  the  actual  breaking  of 
the  lifting  ropes,  the  automatic  stop  would  not  be  of  such  importance, 


AUTOMATIC  DEVICES  USED  FOR  STOPPING  CARS  105 

but  there  are  only  a  few  cases  on  record  where  cars  suspended  from  a 
number  of  ropes  have  dropped  through  the  breaking  of  the  latter.  In 
nearly  every  case  the  elevator  attains  a  dangerously  high  velocity  through 
some  disarrangement  of  the  machinery,  or,  as  it  is  generally  expressed, 
the  elevator  "runs  away."  Since  such  is  the  fact,  it  is  evident  that  if  the 
automatic  stops  are  kept  in  perfect  working  order  every  runaway  can 
be  prevented  from  doing  serious  damage,  although  if  the  car  comes 
down  at  a  sufficiently  high  velocity  the  escape  of  water  through  the  relief 
valve  22  will  continue  long  enough  to  permit  it  to  strike  the  bumpers 
rather  hard. 


CHAPTER  XVII 
EFFECT  OF  'STRETCH-ING  OF  THE  ROPES 

Elevator  lifting  ropes  stretch  continually  from  the  first  day  they  are 
used  until  they  are  replaced,  and  the  position  of  each  automatic  stop-ball 
has  to  be  changed  from  time  to  time  to  compensate  for  the  elongation. 
When  the  ropes  are  new  they  stretch  rapidly,  but  after  a  few  months' 
service  they  apparently  stop  stretching  and  remain  at  practically  the 
same  length  until  they  begin  to  reach  the  point  where  they  should  be 
removed,  then  the  stretching  slowly  increases.  To  guard  against  keeping 
in  service  a  rope  that  is  sufficiently  worn  to  be  in  danger  of  giving  out,  it 
is  necessary  to  make  frequent  inspections,  but  these  inspections  cannot 
be  relied  upon  as  infallible  because  even  the  most  experienced  men  are 
not  sure  to  detect  every  flaw.  Examining  grease-covered  ropes  in  service 
is  very  different  from  inspecting  new  ones.  -The  thoroughness  of  the 
operation  can  be  greatly  increased  if  the  ropes  are  well  cleaned  with 
kerosene,  but  even  when  this  is  done  it  only  enables  the  inspector  to 
determine  external  conditions ;  the  condition  under  the  surface  can  only 
be  conjectured.  If  the  outside  strands  are  badly  worn  or  broken,  it  is 
time  to  put  on  a  new  rope.  The  fact  that  the  ropes  begin  to  stretch 
rapidly  when  reaching  the  end  of  their  usefulness  affords  a  means  of 
determining  their  condition  that  should  not  be  overlooked.  Even  if  from 
external  appearance  they  appear  to  be  sound,  they  should  be  mistrusted 
if  there  is  a  noticeable  increase  in  the  rate  of  stretching. 

If  an  elevator  is  provided  with  pilot-valve  control  the  stretching  of 
the  ropes  will  cause  the  car  to  stop  below  the  floors  when  arrested  by 
the  automatic  stop-valves.  Slight  elongations  of  the  ropes  can  be  com- 
pensated for  by  shifting  the  stop-balls  8  and  p  downward.  A  considerable 
elongation  cannot  be  compensated  for  in  this  way,  because  the  effect  of 
changing  the  position  of  the  stop-balls  is  to  cause  the  car  to  stop  even 
with  the  floors,  and  to  shift  the  piston  out  of  position  in  the  cylinder  so 
that  it  will  run  closer  to  the  lower  end.  As  the  clearance  at  each  end  of 
the  cylinder  is  considerable,  the  position  of  the  piston  can  be  changed 
several  inches  without  doing  harm,  but  beyond  this  point  the  lower 
cylinder-head  will  be  struck  by  the  piston  and  possibly  cause  damage. 

If  an  elevator  is  provided  with  hand-rope  control  the  stretching  of 
the  ropes  will  not  affect  the  stopping  of  the  car,  because  this  is  controlled 
by  the  relative  position  of  the  stop-balls  on  the  hand-rope,  and  this  will 

106 


EFFECT  OF  STRETCHING  OF  THE  ROPES 


107 


evidently  remain  unchanged  regardless  of  the  length  of  the  lifting  ropes. 
In  such  elevators  the  effect  of  stretch  in  the  lifting  ropes  is  to  cause  the 
piston  to  run  nearer  to  the  lower  end  of  the  cylinder  and  finally  to  strike 
it  if  the  ropes  are  not  shortened.  The  way  in  which  the  ropes  are 
shortened  can  be  easily  understood  from  Fig.  73,  which  shows  the 
overhead  beams  on  which  the  main  sheaves  are  supported,  the  traveling 


FIG.   73 


sheave  and  the  method  of  securing  the  end  of  the  rope.  In  elevators 
geared  two  to  one,  as  in  this  illustration,  the  ropes  are  fastened  to  the 
overhead  beams,  but  with  higher  gears  they  are  secured  farther  down, 
generally  to  the  beams  that  carry  the  intermediate  sheaves.  The  end  of 
the  rope  is  firmly  fastened  in  a  long  shackle-bolt,  and  when  the  rope  is 
first  installed  its  length  is  made  such  that  the  nut  on  the  bolt  is  at  the 
end.  By  drawing  up  the  bolt,  the  rope  can  be  shortened  several  inches. 
When  the  rope  cannot  be  taken  up  any  more  by  the  bolt,  it  becomes 
necessary  to  cut  a  piece  off  the  end  of  the  rope. 

To  be  able  properly  to  keep  track  of  the  elongation  of  the  ropes  it  is 
advisable  to  place  a  mark  on  some  stationary  surface  in  line  with  lowest 
position  of  some  part  of  the  traveling-sheave  frame;  then  if  the  car  is 
operated  by  a  hand  rope  the  stretching  of  the  lifting  ropes,  as  well  as 
the  amount  of  stretch,  can  be  detected  by  noticing  how  far  the  traveling 
sheave  runs  below  the  datum  mark.  In  the  case  of  elevators  controlled 
by  pilot  valves  the  distance  the  sheave  runs  below  the  mark  will  serve 
to  show  how  near  the  piston  comes  to  striking  the  lower  cylinder-head, 
and  the  ropes  may  be  shortened  before  any  damage  is  done. 

HOW   TO    SHORTEN    THE   ROPES. 

The  first  thing  to  do  is  to  ascertain  how  much  to  reduce  the  length. 
This  can  be  determined  by  measuring  how  far  the  traveling  sheave  runs 


io8  HYDRAULIC  ELEVATORS 

below  the  proper  position  and  multiplying  this  by  the  gear  of  the  machine. 
For  example,  if  the  sheave  runs  three  inches  below  the  datum  mark  and 
the  gear  is  four  to  one,  the  ropes  will  have  to  be  shortened  one  foot. 
The  gear  can  always  be  ascertained,  as  it  is  equal  to  the  number  of 
times  the  ropes  run  up  from  the  traveling  sheaves.  Having  decided 
how  much  to  take  out  of  the  ropes,  the  next  step  is  to  run  the  car  down 
until  it  rests  upon  the  bumpers,  moving  the  automatic  stop-ball  out  of 
the  way  for  the  purpose.  Then  a  strong  clamp  is  firmly  fastened  to  the 
ropes  several  feet  below  the  ends,  and  this  is  drawn  up  by  means  of  a 
tackle-block  firmly  fastened  to  the  beams  that  sustain  the  shackle-bolts, 
until  the  latter  have  been  raised  enough  to  be  free.  The  shackles  are 
then  removed,  the  ropes  are  shortened  the  proper  amount  and  the  shackles 
replaced,  after  which  the  ropes  are  drawn  up  by  means  of  the  tackle 
to  raise  the  shackle-bolts  high  enough  to  run  the  nuts  on  their  ends. 
,  There  should  be  check-nuts  on  all  the  bolts,  and  in  addition  a  safety-pin 
should  be  passed  through  a  hole  in  the  end  of  the  bolt  that  there  may 
be  no  danger  of  the  bolt  working  off.  This  danger  is  greater  than 
might  be  supposed,  as  the  impression  naturally  would  be  that  there  is  no 
movement  of  a  rotative  kind  which  would  tend  to  loosen  the  nuts.  On 
the  contrary,  there  is  a  strong  force  all  the  time  tending  to  twist  each 
rope.  As  can  be  seen,  when  tension  is  placed  upon  the  ropes  it  acts  to 
untwist  them,  and  if  the  shackle-bolts  were  held  in  frictionless  bearings 
they  would  rotate,  the  number  of  turns  increasing  as  the  strain  is 
increased.  On  removing  the  strain,  the  ropes  would  twist  up  again  and 
rotate  the  shackle-bolts  in  the  opposite  direction.  When  the  traveling 
sheave  is  moving  down  to  lift  the  car,  the  strain  on  the  ropes  is  greater 
than  when  it  is  moving  upward  to  lower  the  car;  therefore,  the  shackle- 
bolts  are  actually  subjected  to  strong  forces  that  tend  to  turn  them  in 
one  direction  when  the  elevator  ascends,  and  in  the  opposite  direction 
when  it  descends.  On  this  account,  if  single  nuts  were  used  they  would 
work  loose  in  a  short  time,  and  even  check-nuts  are  liable  to  work  free, 
hence  the  necessity  of  using  safety-pins.  The  best  plan  of  all,  however, 
is  to  fasten  the  shackle  ends  by  means  of  a  piece  of  wire  passing  from 
one  to  the  other,  so  as  to  prevent  rotation  as  far  as  possible. 

The  course  of  procedure  when  shortening, the  ropes  is  as  follows:  If 
the  shackle-bolt  is  of  the  design  shown  in  Fig.  73,  an  enlarged  view 
of  which  is  given  in  Fig.  74,  the  ends  are  straightened  so  the  clamp  A 
may  be  removed;  then  the  rope  can  be  withdrawn  and  the  wire  binding 
taken  off.  The  old  bend  in  the  rope  is  then  straightened  and  another 
bend  is  made  far  enough  down  to  shorten  the  rope  the  required  amount. 
A's  the  rope  is  stiff,  strong  clamps  will  be  needed  to  bend  it  snugly 
around  the  center  piece.  While  still  clamped,  the  binding  wire  is  wound 


EFFECT  OF  STRETCHING  OF  THE  ROPES 


109 


on  as  tightly  as  possible,  and  if  the  distance  between  the  end  and  the 
upper  position  of  traveling  sheave  permits  there  is  no  objection  to 
making  the  wire  binding  six  inches,  or  even  a  foot,  long.  The  ends  of 
the  wire  should  be  turned  outward  and  upward,  as  shown  in  Fig.  74, 
otherwise  the  rope  may  be  drawn  through  the  binding  wire.  If  the  end 


FIG.   74 


FIG.   75 


FIG.   76 


is  unraveled  and  wound  around  the  body  of  the  rope,  and  then  covered 
with  the  binding  wire,  the  job  will  be  much  stronger,  although  it  may 
not  look  so  well. 

TYPE  OF  SHACKLE  USED. 

The  shackle  shown  in  Fig.  74  is  not  as  generally  used  as  the  type  in 
which  the  end  of  the  rope  is  fastened  in  a  conical  ring,  with  the  ends  of 
the  wires  bent  over  to  form  an  enlargement  to  prevent  pulling  the  rope 
through  the  ring.  This  kind  of  fastening,  when  properly  made,  is  best 
of  all,  and  will  hold  more  securely  than  the  rope  itself.  The  shape  of 
this  shackle  is  shown  in  Figs.  75  and  76.  In  some  cases  the  bolt  is  made 
part  of  the  shackle,  and  in  others  it  is  connected  by  means  of  a  pin,  as 
in  the  illustrations.  To  secure  the  end  of  the  rope  a  binding  band  of 
wire  is  first  put  on  at  a  distance  from  the  point  where  the  rope  is  to  be 
cut  off  that  will  leave  ends  long  enough  to  bend  over  and  fill  the  cone  cup 
to  the  top,  as  illustrated  in  Fig.  77,  a  a  representing  the  point  at  which 
the  rope  is  to  be  cut  off,  b  being  the  binding  band.  This  band  is  made 
of  soft,  iron  wire  (about  No.  20),  and  to  secure  the  ends  of  the  wire 
firmly  and  neatly  the  winding  should  be  done  as  shown  in  Fig.  78,  the 
starting  end  a  being  run  along  in  the  space  between  the  strands  of  the 


no 


HYDRAULIC  ELEVATORS 


rope,  the  first  turn  of  the  band  passing  over  the  end,  as  shown  at  c,  all 
the  other  turns  being  wound  to  the  left.  The  band  should  be  about 
three-quarters  of  an  inch  long,  and  the  ends  a  and  b  are  to  be  twisted 
together,  and  tucked  under  the  band  in  one  of  the  spaces  between  the 
strands. 

It  is  necessary  to  put  this  band  on  before  cutting  the  rope  off,  to 
prevent  untwisting.     It  is  also  advisable  to  place  a  temporary  band  just 


FIG.  77  FIG-  78 

below  the  cutting-off  point,  to  facilitate  the  cutting.  For  the  latter  pur- 
pose a  good  hack-saw  is  best,  although  a  half-round  file  can  be  used, 
especially  where  there  is  no  way  of  holding  the  rope  firmly.  After  the 
rope  has  been  cut  off,  it  is  passed  through  the  shackle  in  the  manner 
shown  in  Fig.  76  and  the  ends  of  the  wire  spread  out.  Next,  the 
ends  are  bent  over  in  the  manner  illustrated  in  Fig.  79,  but  not  as  in 
Fig.  80.  The  latter  way  is  easier  and  may  on  that  account  be  resorted 
to,  but  it  will  not  hold  the  rope  safely  under  a  heavy  strain,  as  can 
be  easily  realized  by  looking  at  Figs.  81  and  82.  In  Fig.  81  it  can  be 


FIG.  79  FIG.  80  FIG.  81  FIG.   82 

seen  that  the  ends  of  the  wire  will  be  held  against  the  sides  of  the 
cone  by  friction  and  the  tension  of  the  rope  will  draw  the  wires  through, 
changing  the  position  of  the  bend,  as  indicated  by  the  dotted  curves  b,  c, 
until  the  rope  is  pulled  entirely  out  of  the  shackle.  With  the  turned-in 
ends  of  Fig.  82  there  is  no  possibility  of  pulling  out.  After  the  ends 
have  been  properly  bent,  the  rope  is  pulled  into  the  shackle  by  means 
of  tackle,  or  screws,  and  the  spaces  between  the  bent  ends  of  the  wire 
are  filled  with  molten  babbitt  metal,  or  zinc.  Sometimes  lead  is  used,  but 
it  is  too  soft  to  be  reliable. 


EFFECT  OF  STRETCHING  OF  THE  ROPES 


in 


When  new  ropes  are  put  on  they  are  fastened  at  the  ends  in  the 
manner  stated.  The  easiest  way  is  to  remove  and  replace  one  rope  at  a 
time,  first  running  the  car  down  to  the  bottom  of  the  building  and 
shutting  the  supply-pipe  valve.  In  putting  on  the  ropes  that  connect 
with  the  independent  counterbalance,  they  must  be  made  of  such  length 
that  the  car  will  rest  on  the  bumpers  before  the  counterbalance  strikes 
the  overhead  beams,  and  when  the  car  runs  up  to  the  top  of  the  building 
the  counterbalance  must  strike  its  bumper  before  the  car  reaches  the 
beams.  The  proportionate  lengths  of  the  ropes  are  shown  in  Figs.  83 


Counterbalance 


FIG.  83 


FIG.  84 


and  84.  In  Fig.  83,  if  the  ropes  were  so  short  that  the  counterbalance 
would  strike  the  beams  first,  the  ropes  would  undoubtedly  be  pulled 
apart.  In  Fig.  84,  if  the  car  ran  into  the  overhead  beams  before  the 
counterbalance  struck  the  bumper,  the  ropes  would  be  likewise  pulled 
apart  by  the  enormous  force  due  to  the  momentum  of  the  counter- 
balance. In  the  case  of  Fig.  83  the  broken  ropes  would  drop  down  the 
elevator  well  onto  the  top  of  the  car,  possibly  with  serious  results  to  the 
passengers.  In  the  case  of  Fig.  84  this  also  would  generally  be  the  case, 
as  in  most  buildings  the  counterbalance  runs  in  the  elevator  well  at  the 
side  of  the  car. 


CHAPTER  XVIII 


CONSTRUCTION  OF  TRAVELING-SHEAVE  FRAMES,  FOUN- 
DATIONS AND  SUPPORTS,  TO  AVOID  PISTON 
AND  CYLINDER  FRICTION 

In  previous  illustrations  the  traveling  sheave  has  been  shown  as  if 
moving  unguided  in  its  path.  This  construction  was  universally  employed 
some  years  ago,  and  most  vertical-cylinder  elevators  in  actual  use  are  so 
arranged;  but  nowadays  very  few  machines  are  installed  with  unguided 


[F    F-k 


30 


o    o 
o    o 

o 

o    o 


FIG.  86 


FIG.  85 

sheaves.  The  modern  practice  is  to  construct  a  substantial  frame,  pro- 
vided with  shoes  that  usually  run  on  iron  guides,  to  hold  the  traveling 
sheaves.  A  sheave  frame  of  this  kind,  as  made  by  the  Otis  Elevator 
Company,  is  shown  in  Figs.  85,  86  and  87,  the  first  two  being  end  and 
side  elevations  and  the  third  a  plan  view.  This  frame  consists  of  sides 


112 


CONSTRUCTION  OF  TRAVELING-SHEAVE  FRAMES 


FF  made  of  channel  beams  about  nine  inches  wide,  with  connecting 
pieces  F'  above,  below  and  between  the  sheaves,  guide-holding  channel 
beams  F"  being  placed  at  the  top  and  bottom.  On  the  ends  of  the 
channels  F"  are  secured  guide  shoes  30,  which  run  on  the  guides  G  G. 
The  lower  beam  F"  and  a  similar  one  opposite,  as  clearly  shown  in 
Fig.  85,  form  a  support  for  the  counterbalance  weights,  and  the  distance 
between  the  beams  and  the  lower  sheave  is  sufficient  to  permit  the  use 
of  as  many  weights  as  may  be  required.  The  lower  ends  of  the  side 
frames  F  F  are  reinforced  by  flat  plates  riveted  to  them,  so  as  to  afford 
proper  bearing  for  the  trunnions  of  a  crosspiece  through  which  the  upper 
ends  of  the  piston-rods  pass. 

The  construction  of  this  piston-rod  connection  is  shown  in  Fig.  88, 
which  also  shows  a  section  through  the  lower  ends  of  the  side  frames 
F  F,  from  which  the  position  of  the  reinforcing  plates  can  be  seen.  The 


21 


FIG.  87 


FIG.  88 


trunnion  ends  of  the  piece  21  are  so  made  that  the  nuts  37  can  press  the 
washers  against  a  shoulder  before  binding  on  the  side  frame,  the  bearing 
38  being  considerably  larger  than  the  screw.  Thus  the  piece  21 
is  free  to  swing  and  thereby  equalize  the  strain  on  the  two  piston- 
rods,  these  passing  through  the  holes  39.  The  equalizing  of  the 
strain  is  not  perfect,  however,  for  if  the  piece  21  is  tilted  much, 
the  nuts  on  the  high  side  will  have  a  bearing  on  the  outside  edge, 
while  the  nuts  on  the  low  side  will  bear  on  the  inner  edge;  therefore 
there  will  be  considerable  difference  in  the  leverage.  Owing  to  this  fact, 
whenever  it  is  found  that  the  crosshead  21  is  out  of  square  with  the 
piston-rods,  it  should  be  trued  up  by  screwing  down  the  nuts  on  the 
high  side. 

The  studs  on  which  the  sheaves  revolve  are  constructed  as  shown  in 
Fig.  89.  They  consist  of  two  parts,  a  steel  center  stud  and  a  brass 
outside  sleeve.  The  stud  reaches  from  outside  to  outside  of  the  frames 
F  F,  while  the  brass  sleeve  is  a  trifle  longer  than  the  width  of  the 
sheave-hub;  hence,  when  the  nuts  are  tightened,  the  sleeve  is  prevented 


114 


HYDRAULIC  ELEVATORS 


from  rotating,  as  a  consequence  of  being  tightly  clamped  between  the 
side  frames.  A  thin  strip  is  set  in  one  side  of  the  stud  32,  and  keyways 
are  cut  on  opposite  sides  of  the  diameter  of  the  brass  sleeve  to  slide 
over  this  strip.  Through  the  center  of  the  stud  an  oil  duct  extends 
from  end  to  end,  so  that  an  oil-cup  may  be  mounted  (see  Fig.  85)  on 
either  side  of  the  sheave.  From  this  central  oiling  channel  radial  ducts 
are  run,  as  shown  in  the  enlarged  view  of  the  stud,  Fig.  90,  and  in  the 
bore  of  the  brass  sleeve  are  grooves  to  match  the  holes  in  the  stud ;  from 
these  grooves  ducts  extend  to  the  outside.  It  will  be  seen  that,  whatever 


FIG.  90 


FIG.  89 

the  position  of  the  stud,  there  will  be  a  clear  passage  from  the  oil-cup  to 
the  outer  surface  of  the  brass  sleeve  which  forms  the  sheave  bearing. 
The  sleeve  has  two  keyways,  so  it  may  be  reversed  when  one  side  is 
worn  out,  the  pressure  on  the  sheave-bearing  being  always  in  the  same 
direction;  and  it  makes  no  difference  how  much  space  there  may  be  on 
the  upper  side;  in  fact,  space  at  this  point  is  a  benefit,  if  anything,  as  it 
serves  to  collect  the  lubricant  so  it  will  be  spread  evenly  over  the  bearing 
surface. 

COMMON    METHOD    OF    ANCHORING    CYLINDERS. 

When  water  under  pressure  is  admitted  to  the  upper  end  of  the 
cylinder  to  lift  the  elevator  car,  it  not  only  acts  to  force  the  piston  down, 


CONSTRUCTION  OF  TRAVELING-SHEAVE  FRAMES  115 

but  by  pressing  against  the  under  side  of  the  upper  head  acts  to  lift 
the  cylinder,  and  unless  the  latter  is  held  down  firmly  it  will  go  up  in 
the  air  and  the  car  will  remain  stationary.  Thus  it  will  be  seen  that  the 
cylinder  must  be  well  anchored  to  keep  it  from  lifting,  particularly  if 
the  elevator  is  geared  high,  say  with  a  ratio  of  four  or  six  to  one.  The 
most  common  way  of  anchoring  vertical  cylinders  is  by  bolting  them 
to  a  foundation  of  such  size  that  foundation  and  cylinder  will  weigh 
more  than  the  pressure  of  the  water  on  the  under  side  of  the  top  cylinder- 


head.  The  cylinder  has  three  strong  lugs  at  the  lower  end,  as  can  be 
seen  in  Fig.  33.  On  the  foundation  is  bolted  a  cast-iron  plate,  1^2 
inches  thick.  The  bolts  extend  nearly  to  the  under  side  of  the  foundation 
and  are  secured  in  anchor  plates  of  sufficient  size  to  enable  the  bolts  to 
lift  the  entire  mass  of  masonry  without  breaking  it.  Three  large  con- 
necting bolts  are  tapped  into  holes  in  the  foundation  plate,  and  the  other 
ends  pass  through  the  cylinder  lugs.  The  general  arrangement  of 
all  these  parts  is  shown  in  Fig.  91.  The  bolts  B  are  about  IT4  inches  in 
diameter  and  long  enough  to  hold  the  lower  head  of  the  cylinder  about 
two  feet  above  the  floor.  By  means  of  nuts,  the  bolts  can  be  adjusted 


n6  HYDRAULIC  ELEVATORS 

alike.  To  prevent  the  cylinder  from  swaying,  it  may  be  steadied  from 
the  walls  or  floor,  according  to  which  may  be  the  more  convenient. 
Sometimes  the  cylinder  is  kept  from  lifting  by  being  secured  to  the 
framing  of  the  building,  where  the  latter  is  of  steel  construction.  In 
such  cases  the  three  bolts  B  simply  serve  to  hold  the  cylinder  in  position, 
but  are  not  counted  upon  to  act  as  part  of  the  anchorage,  because  it  is 
not  good  engineering  to  depend  upon  two  separate  supports  when  the 
construction  is  such  that  it  is  not  possible  to  determine  just  what  portion 
of  the  strain  is  carried  by  each. 

For  quite  a  while  after  an  elevator  is  installed  the  foundation  bolts 
should  be  examined  frequently  to  see  whether  they  have  become  loose, 
in  which  case  they  should  be  tightened.  The  clamps  which  hold  the 
cylinder  against  the  floors  of  walls  should  also  be  tightened  if  there  is 
lost  motion  at  any  point.  The  cylinder  and  the  guides  on  which  the 
traveling-sheave  frame  runs,  should  be  in  line  with  each  other.  As  the 
piston  rods*  are  of  small  diameter  and  project  a  considerable  distance 
above  the  stuffing-boxes,  when  the  sheave  frame  is  in  the  lowest  position 
there  will  not  be  much  side  strain,  even  if  the  cylinder  and  the  guides 
of  the  sheave  frame  are  out  of  line  as  much  as  half  an  inch;  but  the 
stuffing-boxes  will  eventually  wear  away  on  the  side  where  the  rods  rub 
hard,  so  that  it  will  be  difficult  to  keep  the  packing  tight.  On  this 
account,  if  it  is  found  that  the  alinement  is  not  perfect,  the  upper  end 
of  the  cylinder  should  be  shifted.  Usually  this  can  be  done  easily  by 
slacking  up  the  clamps  and  putting  in  or  taking  out  a  liner.  It  may  be 
necessary,  however,  to  cut  away  part  of  the  flange  of  the  girder  that 
the  cylinder  rests  against,  in  order  to  get  the  parts  into  line.  If  this 
should  be  the  case,  it  is  always  preferable  to  shift  the  sheave  guides, 
unless  it  is  certain  that  the  girder  flange  can  be  cut  away  without  weak- 
ening it,  however  slightly.  As  a  rule,  if  the  part  to  be  cut  away  is  very 
close  to  the  wall  or  other  support  of  the  girder,  there  will  be  no  harm 
done  by  cutting  into  the  flange,  say,  a  quarter  or  half  of  an  inch,  but  if 
the  cutting  would  have  to  be  done  at  a  point  near  the  center  of  the  span 
it  would  be  better  not  to  attempt  it  unless  assured  by  the  designer  of 
the  building  that  it  can  be  done  safely.  These  girders  are  very  accurately 
calculated  by  designing  engineers  with  regard  to  withstanding  strains, 
and,  although  a  large  margin  of  safety  is  allowed,  the  removal  of  a 
portion  of  a  flange  might  reduce  the  stiffness  to  an  injurious  extent. 

HOW    TO    STRENGTHEN    SHEAVE    SUPPORTS. 

Not  only  must  the  lifting  cylinder  be  properly  anchored,  but  the 
stationary  intermediate  sheaves  must  be  secured  so  that  the  rope  strain 
will  not  pull  down  their  supports.  This  will  be  understood  from  Fig.  92, 


B 


1} 


Beam- 

1            Sheave. 

' 

Beam 

' 

FIG.  93 


FIG.  94 


FIG.  92 


n8 


HYDRAULIC  ELEVATORS 


in  which  it  will  be  seen  that  only  a  portion  of  the  total  downward  pull 
of  the  piston  acts  on  the  car-lifting  rope  R,  the  balance  being  impressed 
directly  upon  the  supports  of  the  stationary  sheaves  S  and  S'.  In  this 
diagram  the  machine  is  geared  six  to  one,  so  that  one-sixth  of  the  pull 
of  the  piston  acts  on  the  lifting  rope  R,  and  the  other  five-sixths  on  the 
supporting  beams  B  B' ',  two-fifths  coming  on  the  first-named  and  three- 
fifths  on  the  second.  In  all  first-class  buildings,  the  supports  for  these 
sheaves  are  generally  strong  enough,  but  occasionally  they  are  not,  either 
through  faulty  calculation  on  the  part  of  the  elevator  engineers  or  cheap 


FIG.  95 

construction.  The  principal  elevator  manufacturers  employ  engineers 
who  can  calculate  accurately  every  part  of  an  elevator  structure.  Others, 
however,  employ  men  who  have  no  technical  knowledge,  but  work  out 
everything  by  "practical  experience"  and  the  "rule  of  thumb,"  and, 
although  such  men  generally  err  by  making  things  stronger  than  neces- 
sary, in  their  desire  to  be  on  the  safe  side,  they  sometimes  make  serious 
mistakes  and  get  things  entirely  too  weak.  As  to  the  strength  of  the 


CONSTRUCTION  OF  TRAVELING-SHEAVE  FRAMES  119 

building,  there  is  not  so  much  certainty.  First-class  office  buildings  are 
sure  to  be  of  ample  strength  at  every  point,  but  cheaply  constructed 
apartment  houses  and  family  hotels,  with  cast-iron  columns  and  bolted 
joints,  cannot  be  counted  upon  as  being  reliable  in  every  particular. 
Where  the  floor  beams  of  such  buildings  are  not  stiff  enough  to  support 
the  beams  B  B' ,  the  construction  can  be  improved  by  means  of  braces 
extending  from  the  beams  that  sustain  the  supports  B  B'  to  the  floor 
below,  or,  if  necessary,  to  the  second  or  third  floor  below.  In  extreme 
cases,  where  it  does  not  appear  safe  to  trust  to  the  building  itself,  a 
perfectly  rigid  construction  can  be  obtained  by  running  braces  from  the 
supports  B  B'  to  the  cylinder,  so  that  the  strains  will  be  limited  to  the 
elevator  apparatus.  It  is  understood  that  this  construction  has  been 
adopted  by  elevator  builders  in  certain  Western  cities,  for  cases  where 
buildings  are  cheaply  built. 

The  building  may  be  strong  enough  to  afford  proper  support  to  the. 
beams  B  B' ,  yet  these  may  not  be  of  proper  size  to  give  the  required 
stiffness  if  improperly  located.  If  they  are  sustained  by  parallel  beams 
oY  walls,  as  indicated  in  Fig.  93,  little  harm  will  be  done  through  lack 
of  stiffness ;  but  if  they  are  supported  by  walls  or  beams  at  right  angles, 
as  in  Fig.  94,  there  may  be  trouble,  for  as  can  be  clearly  seen  the  beam  B 
will  spring  more  than  B' ,  owing  to  its  greater  length,  and  this  will  have 
the  effect  of  throwing  the  sheave  bearings  out  of  line,  as  indicated  in 
Fig.  95.  When  the  support  B  sags  more  than  Br,  if  both  beams  become 
twisted  so  as  to  remain  parallel  with  the  sides  of  the  sheave,  there  will 
be  little  harm  done;  if,  however,  the  beams  do  not  twist,  but  remain  in 
the  vertical  position,  as  shown,  the  sheave-shaft  will  be  out  of  alinement 
with  the  bearings,  and  will  run  hot  or  score,  until  the  corners  wear  away 
enough  to  give  a  good  bearing.  The  easiest  way  to  surmount  this  diffi- 
culty, if  the  support  B  does  not  sag  much,  is  to  line  up  the  bearings 
parallel  with  the  sheave-shaft.  If  the  sagging  is  considerable,  the  beam 
should  be  propped  up,  if  this  can  be  conveniently  done,  or  it  may  be 
stiffened  by  riveting  a  plate  on  the  side  of  the  web,  taking  the  strain  off 
the  sheave  while  the  plate  is  being  put  on. 


CHAPTER  XIX 
WHY  THE  PISTON  IS  WEIGHTED 

In  each  of  the  sectional  drawings  of  vertical  cylinders  already  shown 
the  piston  is  represented  with  a  number  of  counterbalance  weights  resting 
upon  it,  and  no  doubt  many  readers  have  wondered  why  this  construction 
is  used,  inasmuch  as  it  increases  the  length  of  the  cylinder  and  therefore 
its  cost.  The  reason  can  be  made  perfectly  clear  by  the  aid  of  Fig.  33. 
Suppose  that  the  piston  has  just  reached  the  point  where  the  automatic 
stop  valve  begins  to  swing  around  to  the  right  side  to  cut  off  the  outflow 
of  water,  and  that  after  the  piston  passes  over  one-half  the  remainder 
of  the  stroke  the  automatic  valve  closes  the  outlet  completely,  then,  if 
the  piston  still  persists  in  going  down,  the  water  under  it  must  lift  the 
relief  valve  22  in  order  to  escape.  If  the  car  is  running  upward  very 
fast  at  this  instant,  as  is  likely  to  be  the  case  if  the  load  is  light,  the 
momentum  will  be  great  and  the  car  will  tend  to  keep  up  its  motion 
after  the  stop  valve  has  closed  the  outlet.  The  momentum  of  the  trav- 
eling sheave  and  piston  will  also  be  considerable,  but  not  as  great  as 
that  of  the  car,  owing  to  the  lower  velocity.  The  sheave,  however,  will 
move  down  as  rapidly  as  the  car  goes  up,  but  the  piston  might  not  do 
so,  because  to  descend  with  a  velocity  equal  to  that  of  the  traveling 
sheave  it  would  not  only  have  to  overcome  the  friction  of  all  its  parts, 
but  it  must  also  have  sufficient  energy  left  to  force  the  water  through 
the  valve  22.  The  momentum  of  a  light  piston  would  be  insufficient  to 
do  all  this  work;  therefore  it  would  lag  behind  and  the  piston-rods 
would  slacken  up ;  in  extreme  cases  the  rods  might  be  forced  up  through 
the  crosshead  in  the  traveling-sheave  frame. 

Thus  far  I  have  considered  only  what  would  take  place  if  the  car 
were  arrested  by  the  action  of  the  automatic  stop  while  ascending,  but 
it  can  be  readily  seen  that  if  at  any  time  during  the  up  trip  the  operator 
closes  the  main  valve  too  quickly  when  the  speed  is  high,  the  same  effect 
will  be  produced.  To  prevent  such  an  occurrence  the  piston  is  weighted. 
It  may  be  suggested  that  it  would  be  preferable  to  make  the  piston 
heavier,  instead  of  adding  counterbalance  weights,  and  this  is  very  true ; 
but  heavier  castings  would  have  to  be  handled  and  there  is  room  for 
an  honest  difference  of  opinion  whether  it  would  be  advisable  to  save 


WHY  THE  PISTON  Is  WEIGHTED  121 

pieces  by  increasing  the  weight  of  a  part  which  has  to  be  finished  in  a 
lathe,  and  which  in  the  process  of  erection  has  to  be  handled  with 
great  care. 

TO  PREVENT  FRICTION. 

As  the  weight  of  the  piston  alone  causes  it  to  descend,  it  is  evident 
that  it  is  necessary  to  restrict  the  resistance  to  motion  to  a  minimum  at  all 
times,  otherwise  the  stopping  and  starting  on  the  up  trips  may  be  very 
unsatisfactory.  If  the  piston  packing  is  too  tight  sufficient  friction  may 
be  developed  to  retard  it  unduly  when  the  car  stops  on  down  trips,  even 
if  the  stops  are  not  abnormally  sudden.  If  the  cylinder  is  not  well 
lubricated,  also,  the  friction  may  increase  enough  to  interfere  with  the 
movement  of  the  piston;  therefore,  this  point  should  not  be  overlooked. 
An  oil-cup  is  provided  at  the  side  of  the  cylinder,  and  if  this  cup  is  filled 
every  ten  days  or  two  weeks  and  the  cocks  opened  for  about  half  an 
hour,  the  oil  will  run  in  and,  being  lighter  than  the  water,  will  rise  to  the 
surface  and  collect  under  the  bottom  of  the  piston,  whence  it  will  grad- 
ually spread  over  the  cylinder  surface.  After  the  oil  has  drained  out  of 
the  cup,  the  circulating  cocks  must  be  closed ;  if  they  are  not,  water  will 
escape  and  the  car  will  settle  while  stopped  at  the  landing.  Cylinder-oil 
is  the  proper  lubricant  for  this  purpose.  It  is  seldom  necessary  to  oil  the 
cylinder  oftener  than  once  in  ten  days,  because  the  water  itself  acts  as  a 
lubricant.  If  the  cylinder  requires  lubrication  it  can  be  detected  by  a 
rumbling  and  also  by  unevenness  of  motion.  These  symptoms,  however, 
are  not  always  an  indication  that  the  cylinder  requires  oiling,  as  they 
may  be  produced  by  inequality  of  tension  in  the  piston-rods,  which  will 
cause  one  side  of  the  piston  to  sag  and  bind  in  the  cylinder.  This 
condition  can  be  detected  by  examining  the  cross  head  plate  in  the 
traveling-sheave  frame,  to  see  if  it  is  square  with  the  piston-rods,  and 
also  by  noticing  if  the  rumbling  and  chattering  are  unequal  on  the  up 
and  down  trips.  If  there  is  more  noise  when  the  piston  is  going  up,  it 
indicates  that  the  rods  are  not  strained  equally. 

In  addition  to  keeping  the  cylinder  properly  lubricated,  and  the 
piston  packing  properly  adjusted,  it  is  necessary  to  keep  the  relief 
valve  22  in  proper  working  order.  A  light  spring  is  used  to  hold  this 
valve  to  its  seat  because  very  little  tension  is  required,  but  if  it  becomes 
clogged  it  may  not  move  freely  enough  to  allow  water  to  pass  through 
the  valve  as  fast  as  necessary  to  avoid  holding  the  piston  back,  causing 
the  piston-rods  to  slacken  up.  When  the  car  is  going  down,  as  the 
water  in  the  cylinder  simply  circulates  from  the  top  to  the  bottom  of  the 
piston,  the  pressure  above  and  below  the  valve  22  is  nearly  equal,  hence 
slight  pressure  is  needed  to  hold  the  valve  to  the  seat.  When  the  car  is 
going  up  the  lower  end  of  the  cylinder  is  connected  with  the  discharge 


122  HYDRAULIC  ELEVATORS 

pipe,  so  that  practically  all  the  pressure  is  removed  from  under  the 
valve  22,  hence  no  spring  pressure  is  required  to  keep  it  closed.  On 
an  up  trip,  when  the  elevator  is  stopped  either  by  moving  the  main 
valve  or  the  automatic  valve,  the  momentum  of  the  descending  piston 
will  act  to  compress  the  water  in  the  lower  end  of  the  cylinder  and  thus 
force  it  up  through  the  valve  22  into  the  lower  end  of  the  circulating 
pipe.  If  the  valve  22  lifts  easily  and  opens  wide  enough,  the  water  will 
be  forced  through  it  as  fast  as  may  be  necessary  to  prevent  holding  the 
piston  back;  but  if  the  valve  moves  hard,  or  does  not  lift  enough,  the 
piston  will  be  held  back  and  the  piston-rods  will  slide  down  through  the 
holes  in  the  upper  end,  until  the  momentum  of  the  car  and  traveling 
sheave  is  absorbed,  then  the  weight  of  these  parts  will  cause  them  to 
descend  and  pull  the  piston-rods  back  until  they  reach  their  bearing, 
when  the  car  will  stop  with  a  jolt. 

The  automatic-valve  chamber  is  provided  with  openings  opposite  the 
valve  22  to  permit  of  easy  aclcess  to  the  latter.  To  open  up  this  valve 
chamber  it  is  necessary  to  draw  the  water  from  the  circulating  pipe 
and,  unless  the  piston  is  perfectly  tight,  also  from  the  cylinder.  Of 
course  it  will  be  understood  that  the  valve  in  the  supply  pipe  must  be 
closed  first.  It  is  considerable  of  a  job  to  get  at  the  valve  22,  but 
fortunately  it  is  not  often  necessary ;  for  unless  the  elevator  behaves 
unsatisfactorily  in  making  stops  on  the  up  trips  it  may  be  taken  for 
granted  that  there  is  nothing  the  matter  with  this  valve.  Then,  too,  if 
such  stops  are  not  as  perfect  as  they  should  be,  the  fault  may  not  be 
in  the  valve  22,  but  in  the  cylinder,  hence  the  latter  should  be  put  in 
proper  condition  before  attempting  to  clean  out  the  chamber  of  the 
valve  22. 


CHAPTER  XX 

THE  ELECTRICAL  FEATURES  OF  VERTICAL-CYLINDER 
ELEVATORS,  WITH   MAGNET   CONTROL,   OPERA- 
TION AND  CARE  OF  PILOT  VALVES  AND 
CONNECTING  MECHANISMS 

This  chapter  will  be  confined  to  a  consideration  of  the  purely  electrical 
features  of  vertical-cylinder  elevators  and  the  mechanical  devices  that 
operate  in  connection  with  them.  The  general  arrangement  of  the 
various  parts  of  a  magnetically  controlled  vertical-cylinder  hydraulic 
elevator  may  be  seen  by  reference  to  Fig.  96,  which  shows  the  arrange- 
ment of  the  pilot  valve  and  the  secondary  pilots  used  for  operation  by 
battery,  or  alternating  current,  the  electrical  features  being  the  same  as 
in  those  designed  to  be  operated  by  current  taken  from  an  incandescent- 
lighting  circuit.  The  magnets  that  move  the  pilot  valve  are  located  at  A. 
They  are  connected  with  the  batteries  and  the  floor  controller  D  by 
means  of  wires  carried  in  the  cable  B.  The  arms  C  of  the  floor  con- 
troller are  connected  with  relay  magnets,  contained  in  the  magnet  box 
shown,  by  wires  in  the  cable  E,  while  other  wires  in  the  cable  F  connect 
the  relay  magnets  with  the  push-buttons  located  at  the  sides  of  the 
elevator  doors  on  the  several  floors.  From  a  point  G  located  half  way 
up  the  elevator  well  is  suspended  a  cable  H  which  carries  the  wires 
connecting  with  the  push-buttons  in  the  car.  The  manner  in  which  the 
relay  magnets  are  connected  with  the  floor  and  car  push-buttons,  and 
also  with  the  contact  rollers  on  the  floor  controller,  is  clearly  shown  in 
the  wiring  diagram,  Fig.  59. 

The  purpose  of  the  floor  controller  is  to  control  the  direction  of 
movement  of  the  car  whenever  a  push-button  is  depressed.  If  the 
car  is  above  the  floor  with  which  the  button  corresponds  it  will  run 
down,  and  if  below  the  floor  it  will  run  up  to  that  floor.  From  this  it 
will  be  seen  that  the  floor  controller  is  virtually  a  reversing  switch,  so 
made  that  the  point  at  which  it  effects  the  reversal  is  controlled  by  the 
position  of  the  car  in  the  elevator  well. 

Two  views  of  the  floor  controller  are  shown  in  Fig.  97,  and  from 
these  it  will  be  seen  that  the  contact  arcs  d  d'  of  Fig.  59  are  replaced  in 
the  actual  machine  by  the  spiral  strips  a  a',  Fig.  97.  This  construction 
is  used  to  permit  the  contact  rollers  b  b  to  pass  over  the  break  between 
the  ends  of  a  and  a',  moving  with  sufficient  velocity  to  prevent  injurious 
sparking.  The  break  D,  Fig.  59,  is  shown  at  d  in  Fig.  97.  In  order 

123 


FTG.   96 

GENERAL   ARRANGEMENT    OF   VARIOUS    PARTS    OF   A    MAGNETICALLY 
CONTROLLED  ELEVATOR 


THE  ELECTRICAL  FEATURES  OF  VERTICAL-CYLINDER  ELEVATORS  125 

that  the  contact  rollers  b  b  may  pass  from  the  contact  strip  a  to  the 
strip  a',  or  vice  versa,  at  the  right  time,  the  drum  of  the  floor  controller 
is  rotated  by  means  of  a  sprocket-wheel  and  the  chain  J,  Fig.  96,  and 
the  gearing  is  proportioned  to  allow  the  roller  corresponding  to  each 
floor  to  pass  the  break  d  at  the  time  the  car  is  passing  the  floor.  The 
break  d  consists  of  a  "dead"  piece  of  such  length  that  the  circuit  between 
the  roller  and  the  contact  strip  is  broken  shortly  before  the  car  is  even 
with  the  floor,  whether  going  up  or  down.  The  distance  from  the  floor 


FIG.   97 

at  which  the  break  occurs  is  just  enough  to  cause  the  car  to  come  to  a 
stop  on  a  level  with  the  floor. 

NEED  OF  KEEPING  CONTACTS  BRIGHT. 

The  current  passing  through  the  floor  controller  is  very  weak  (about 
one  ampere),  so  that  it  cannot  cause  much  sparking  when  the  rollers 
b  b  pass  off  the  ends  of  the  contact  strips ;  nevertheless,  if  the  ends  of 
the  contacts  are  permitted  to  become  badly  burned  the  duration  of  the 
sparking  will  become  increased,  and  this  will  not  only  cause  increased 
burning  at  the  ends  of  the  strips  with  each  succeeding  break,  but  it  will 
also  cause  the  car  to  travel  slightly  farther  before  stopping.  Thus  it  will 
be  seen  that  to  prevent  rapid  deterioration  of  the  ends  of  the  contact 
strips  a  a' ,  and  of  the  rollers  b  b,  as  well  as  to  secure  accurate  stopping 
of  the  car,  it  is  necessary  to  keep  these  parts  bright  all  the  time.  It  is 
also  essential  to  keep  the  surfaces  of  the  contact  strips  bright  all  over, 
for,  as  will  be  seen  in  Fig.  59,  the  current  that  actuates  the  valve-lifting 
magnets  passes  through  these  strips,  and  also  through  the  relay  magnets, 
and  if  sufficient  corrosion  or  dirt  should  accumulate  to  stop  the  flow  of 


126  HYDRAULIC  ELEVATORS 

current,  or  even  to  reduce  its  strength  so  that  it  would  not  hold  the  relay 
magnets  closed,  the  circuit  would  be  broken  and  the  car  would  stop.  The 
sprocket-chain  /  must  be  kept  properly  adjusted  so  as  not  to  slip  off  the 
teeth  of  the  sprocket-wheel,  but  at  the  same  time  it  should  not  be  so 
tight  as  to  lift  on  the  controller  shaft  sufficiently  to  cause  the  bearing  to 
run  hot.  The  drum  of  the  controller  is  arranged  to  run  on  a  thread  so 
that  it  may  travel  endwise  as  it  rotates,  and  thus  keep  the  contact  rollers 
b  b  on  the  contact  strips  a  a'.  The  pitch  of  the  thread  on  which  the  drum 
runs  is  the  same  as  that  of  the  strips  a  a'.  The  floor  controller  shown 
in  Fig.  97  is  slightly  different  from  that  shown  in  Fig.  96,  in  that  it  has 
a  large  driving  sprocket  on  the  end  of  the  shaft,  in  place  of  a  "small 
sprocket  and  a  worm-gear  reduction;  in  every  other  respect  the  con- 
struction is  identical. 

CARE  OF  THE  RELAY   MAGNETS. 

In  the  magnet  box  shown  in  Fig.  96  are  placed  the  relay  magnets, 
and  as  the  successful  operation  of  the  elevator  depends  on  the  proper 
working  of  these,  they  should  be  examined  frequently  and  kept  in  good 
condition.  All  they  require  ordinarily  is  to  be  kept  free  from  dust,  and 
the  contacts  should  be  kept  bright  to  prevent  injurious  sparking.  The 
best  way  to  keep  contact  surfaces  bright,  on  both  the  floor  controller  and 
the  relay  magnets,  is  by  the  use  of  fine  sandpaper,  about  No.  o.  To 
prevent  injury  to  the  insulation,  the  parts  through  which  electric  currents 
pass  must  be  kept  well  protected  from  water,  and  even  moisture.  As  a 
rule,  when  the  apparatus  is  installed  all  the  electrical  parts  are  placed 
where  they  are  not  exposed,  but  sometimes  in  making  changes  in  a 
building  the  necessity  of  keeping  these  parts  perfectly  dry  is  lost  sight 
of,  and  then  trouble  begins.  The  only  parts  of  the  electrical  apparatus 
that  cannot  very  well  be  removed  from  where  they  are  liable  to  be 
damaged  by  water  are  the  two  sets  of  magnets  that  actuate  the  pilot 
valve ;  these  must  necessarily  be  placed  at  A,  Fig.  96.  To  protect,  them 
as  much  as  possible,  they  are  insulated  as  a  whole  from  the  valve  casing 
in  the  manner  shown  in  Figs.  53  and  49,  the  former  being  the  type  of 
controller  shown  in  Fig.  96  and  the  latter  the  type  used  when  the 
operating  current  is  taken  from  a  lighting  circuit.  In  Fig.  53  it  will  be 
seen  that  the  bolts  A'  that  hold  the  magnet  stand  to  the  valve  plate  A 
are  well  insulated,  and  the  valve- rod  D  is  insulated  at  E;  so  that  if  a 
leak  should  develop  in  the  insulation  between  the  wire  coils  and  this  part 
of  the  magnet  frame  it  would  do  no  damage. 

In  Fig.  49  an  insulating  plate  D"  separates  the  magnets  from  the 
plate  E,  and  the  bolts  E'  are  also  insulated  from  it.  The  magnet  rock- 
lever  A  is  insulated  from  the  connecting-rod  Jj  at  the  joint  E".  If  the 


THE  ELECTRICAL  FEATURES  OF  VERTICAL-CYLINDER  ELEVATORS  127 

plate  E  is  kept  clean  there  is  little  danger  of  impairing  the  insulation  D" , 
because  the  surface  surrounding  the  stuffing-box  of  the  pilot  valve  is 
lower  than  thaj:  on  which  the  magnets  are  mounted ;  there  is  also  a  drain- 
pipe to  carry  off  any  water  that  may  escape  from  the  stuffing-box,  and 
if  the  surface  is  not  covered  with  dust  and  lint,  which  would  cause  water 
to  creep  up  by  capillary  attraction,  the  insulating  plate  D"  will  remain 
dry.  Holes  are  drilled  through  the  plate  E  for  the  bolts  E' ',  and  other 
holes  are  drilled  opposite  the  screws  that  hold  the  magnet  cores  to  the 
base.  If  it  is  desired  to  remove  the  magnets  it  is  important  to  be  sure 
that  the  current  is  turned  off,  as  otherwise,  if  there  should  be  a  leak 
between  the  magnet  coil  and  the  core,  the  screw-driver  coming  in  contact 
with  the  sides  of  the  hole,  which  it  would  be  sure  to  do,  would  form  a 
ground  connection. 

In  the  construction  shown  in  Fig.  53  there  is  as  little  liability  of 
injuring  the  insulation  around  the  bolts  as  in  Fig.  49,  as  the  surface  on 
which  the  stuffing-boxes  are  held  is  depressed. 

PROTECTION  FROM  WATER. 

The  only  way  that  water  can  get  onto  the  magnets  in  either  Fig.  53 
or  Fig.  49  is  by  leaking  out  of  the  stuffing-boxes  in  sufficient  quantity  to 
form  a  spray.  If  this  should  happen,  the  best  thing  to  do  would  be  to 
put  up  a  board,  or  a  sheet  of  heavy  cardboard  or  tin.  to  keep  the  water 
off  until  the  stuffing-box  is  repacked.  It  is  not  a  bad  precaution  to  have 
galvanized-iron  boxes  made  to  permanently  cover  the  magnets,  not  only 
to  protect  the  coils  from  unexpected  sprays  of  water  from  the  stuffing- 
boxes,  but  also  to  keep  out  dust. 

The  drain-pipe  that  connects  with  the  depression  in  the  valve  plate 
should  be  kept  clear  all  the  time,  because  the  stuffing-boxes  are  sure  to 
leak  occasionally,  and  if  the  water  cannot  run  off  it  will  fill  up  the 
depression  and  reach  the  insulation. 

The  strainers  through  which  passes  the  water  that  enters  the  pilot 
valve  should  be  cleaned  out  as  often  as  may  be  necessary  to  insure  free 
circulation  of  the  water.  If  this  is  not  done  the  main  valve  will  not 
open  as  rapidly  as  it  should,  and  the  elevator  car  will  not  start  up  quickly 
enough.  No  definite  directions  can  be  given  as  to  the  frequency  with 
which  the  strainers  should  be  cleaned,  as  this  depends  entirely  upon  the 
amount  of  dirt  in  the  water,  and  while  once  a  week  may  be  often  enough 
in  one  case,  once  a  day  may  be  too  seldom  in  others.  About  the  best 
guide  is  in  the  operation  of  the  elevator.  If,  within  a  certain  time  after 
the  strainer  has  been  cleaned,  it  is  found  that  the  starts  are  too  sluggish 
on  the  down  trip,  the  idle  strainer  should  be  tried  and  the  effect  noted. 
If  this  improves  the  starting,  it  indicates  that  the  first  strainer  requires 


128  HYDRAULIC  ELEVATORS 

cleaning.  After  a  few  trials  the  length  of  time  the  strainers  can  be  used 
without  cleaning  will  be  readily  apparent.  On  the  up  trips  of  the  car 
the  condition  of  the  strainers  will  not  have  any  effect  on  the  starting, 
because  the  pilot  valve  is  then  lifted,  and  the  water  above  the  motor 
piston  at  the  top  of  the  main-valve  chamber  escapes  into  the  discharge 
pipe,  the  rapidity  of  discharge  being  controlled  entirely  by  the  opening 
through  the  pilot  valve. 

FOR  REMOVING  THE   MAGNETS. 

If  at  any  time  it  should  be  desired  to  remove  the  magnets  it  can  be 
done  without  disturbing  the  base  plate  or  the  frame  in  Fig.  53,  and  it  is 
advisable  not  to  remove  the  latter  if  the  insulation  is  sound,  because  there 
is  always  a  certain  amount  of  uncertainty  about  securing  perfect  insula- 
tion when  the  plate  is  replaced.  The  magnet  coils  and  plungers  may  be 
removed  by  unscrewing  the  bolts  that  hold  them  to  the  frame,  and  the 
latter  need  not  be  removed  unless  it  is  desired  to  take  out  one  of  the 
valves  D.  In  Fig.  49  the  magnets  can  also  be  removed  by  taking  out  the 
screws  through  the  holes  in  the  valve  plate  E.  The  lever  A  can  be 
removed  by  withdrawing  the  pin  upon  which  it  rocks,  and  this  can  be 
removed  by  loosening  the  set-screw  shown  in  the  drawing. 

No  part  of  the  magnet  apparatus  shown  requires  lubricating,  because 
the  total  movement  of  the  levers  is  so  small  that  the  parts  can  run  dry 
practically  as  well  as  if  lubricated.  If  it  is  felt  that  some  lubrication  is 
necessary,  it  will  be  sufficient  to  remove  the  pins  and  rub  their  surface 
well  with  a  soft-lead  pencil.  It  is  not  advisable  to  use  oil  or  grease  on 
these  joints,  because  such  lubricants  spread  over  the  surface  and  catch 
dust,  increasing  the  danger  of  injuring  the  insulation.  Oil  itself,  if  clean, 
is  a  good  insulator,  but  the  particles  of  dust  that  stick  to  it  are  likely 
to  be  good  conductors.  All  the  bearings  of  the  floor  indicator  should  be 
properly  lubricated,  but  it  is  not  necessary  to  oil  the  rollers  b  b  or 
strips  a  a'. 

PROPER  TREATMENT  OF  CABLES 

The  stationary  cables  B,  E,  F,  Fig.  96,  require  no  especial  attention, 
as  there  is  no  reason  why  they  should  deteriorate,  but  they  should  be 
examined  to  ascertain  if  they  are  exposed  where  they  are  liable  to  be 
injured.  If  they  are  found  to  be  improperly  protected  at  any  point  they 
should  be  shielded  without  delay.  The  flexible  cable  H,  from  the  junction 
G  to  the  car,  requires  frequent  inspection  because  the  continuous  bending 
will  cause  it  to  give  out  at  some  point  sooner  or  later.  If  it  is  found 
to  be  chafed  anywhere  a  thorough  investigation  will  probably  show  that 
it  rubs  against  the  car  or  the  wall  of  the  elevator  well,  and  an  effort 
should  at  once  be  made  to  remedy  the  defect,  either  by  changing  the  end 


THE  ELECTRICAL  FEATURES  OF  VERTICAL-CYLINDER  ELEVATORS  129 

fastenings  so  the  cable  may  run  free,  or  by  covering  any  rough  surfaces 
against  which  it  strikes,  or  by  both  means.  If  the  cable  is  improperly 
hung  or  protected,  the  insulating  covering  will  soon  be  destroyed,  and 
the  wires  may  be  broken  so  that  the  circuit  connection  with  some  of  the 
floors  cannot  be  completed,  'in  which  case  the  car  will  fail  to  respond  to 
the  push-buttons  on  these  floors ;  or,  two  or  more  wires  may  come 
together  and  form  a  short-circuit  which  would  put  the  elevator  entirely 
out  of  service. 

HOW   TO    LOCATE    THE    PILOT   VALVE. 

The  proper  adjustment  of  the  pilot  valve  as  regards  location  is  of 
decided  importance,  as  upon  it  will  depend  the  position  of  the  main 
valve  when  the  elevator  is  at  rest,  and  also  the  velocity  of  the  car.  In 
Fig.  53  the  motor  cylinder  Z  is  so  arranged  that  the  ports  at  both  ends 
are  connected  with  the  discharge  pipe  when  the  elevator  is  not  running, 
hence  the  spring  draws  the  piston-rod  to  the  central  position  when  it 
forces  the  collars  Q  Q'  against  the  collars  N  N'.  From  this  it  can  be  seen 
that  if  the  sleeves  P  P'  are  raised,  the  motor  piston  M  of  the  main  valve 
will  rest  in  a  lower  position  when  the  pilot  valve  is  central,  because 
wherever  the  sleeves  P  P'  may  be  set,  they  will  be  drawn  to  the  central 
position,  with  reference  to  NN',  by  the  spring  S',  and  as  the  elevator 
will  not  stop  until  the  pilot  valve  is  central,  the  shifting  out  of  position 
due  to  the  depression  of  the  piston  in  Z  must  be  in  the  main  valve.  If 
the  sleeves  P  P'  are  lowered,  the  displacement  of  the  piston  M  will  be 
in  the  opposite  direction,  that  is,  upward.  The  movement  of  P  P'  up  or 
down  from  the  position  in  which  they  are  shown  causes  the  piston  in 
the  cylinder  Z  to  stop  either  higher  or  lower  than  shown,  but  it  will  be 
noticed  that  the  cylinder  is  much  longer  than  the  stroke,  to  provide  room 
for  adjustment.  The  stroke  of  the  piston  in  the  cylinder  Z  is  equal  to 
the  difference  between  the  lengths  P  P'  and  N  N'.  In  Fig.  49  the  adjust- 
ment of  the  position  of  the  pilot  valve  is  effected  by  means  of  the  centering 
screws  C  C ,  and  as  will  be  seen  the  result  is  the  same  as  in  Fig.  53 ;  that 
is,  if  the  screws  are  adjusted  so  as  to  lift  the  joint  E",  the  main  valve 
will  be  raised,  and  if  the  adjustment  depresses  E" ,  the  piston  V  will  be 
depressed,  since  the  pilot  valve  must  come  to  the  central  position  to  stop 
the  elevator. 

ADJUSTMENT  TO  REGULATE   SPEED. 

The  effect  produced  by  adjusting  the  pilot  valve  in  the  manner  above 
explained  can  be  understood  readily  from  Fig.  49.  It  shows  the  lower 
valve  V  in  the  stop  position,  and  it  will  be  noticed  that  the  cup  packings 
lap  over  the  ports  considerably  at  both  ends — from  c  to  d  at  the  upper 
end;  and  from  e  to  g  at  bottom— hence  the  valve  can  be  moved  a  distance 


130  HYDRAULIC  ELEVATORS 

equal  to  c  d-\-e  g,  without  setting  the  car  in  motion  in  either  direction. 
This  simply  means  that  the  motor  piston  V  can  be  in  any  position 
between  the  dotted  lines  a  and  b  when  the  car  is  stopped. 

When  the  elevator  runs  down  no  water  is  used;  the  weight  of  the 
car  furnishes  the  moving  force,  and  the  water  is  forced  out  of  the  upper 
end  of  the  cylinder,  down  the  circulating  pipe,  through  the  valve  chamber 
in  the  direction  indicated  by  the  arrows  s  s  s,  through  as  much  of  the 
port  P'  as  may  be  uncovered  by  the  valve  V ,  and  into  the  lower  end  of 
the  cylinder.  The  flow  of  water  is  impeded  slightly  by  the  frictional 
resistance  in  passing  through  the  circulating  pipe,  the  valve  chamber 
and  other  passages,  but  this  is  not  enough  to  prevent  it  from  running 
through  quickly  enough  to  cause  the  car  to  descend  at  a  very  high 
velocity,  especially  if  heavily  loaded.  Furthermore,  whatever  this  resist- 
ance may  be,  it  will  remain  about  the  same  for  all  trips.  To  permit  the 
regulation  of  the  speed  of  the  car,  by  compensating  for  different  loads, 
the  valve  V  is  opened  more  or  less  so  that  the  main  impediment  to  the 
free  circulation  of  the  water  is  the  passage  through  the  holes  in  the  brass 
lining  of  the  valve  chamber,  opposite  the  port  P'.  When  the  car  runs 
up,  the  water  in  the  lower  end  of  the  cylinder  passes  out  through  the 
port  P'  into  the  discharge  pipe  Ds,  and  the  rapidity  with  which  it  can 
escape  will  depend  on  the  amount  of  port  uncovered  by  the  valve  V . 
From  all  this  it  is  evident  that  if  the  car  does  not  run  fast  enough  on 
the  down  trip,  its  velocity  can  be  increased  by  adjusting  the  pilot  valve 
so  the  motor  piston  V  will  rest  lower  when  in  the  stop  position,  which 
means  that  the  end  of  the  lever  {A,  Fig.  49)  must  be  depressed,  and  the 
sleeves  P  P',  Fig.  53,  must  be  raised.  If  this  is  done,  the  valve  V  can  be 
moved  farther  down  when  running,  so  as  to  open  the  port  P'  wider,  and 
thus  permit  the  water  to  circulate  more  rapidly. 

In  the  same  way,  if  the  car  ascends  too  slowly  the  speed  may  be 
increased  by  adjusting  the  pilot  valve  in  the  opposite  direction. 

This  explanation  of  the  adjustment  of  the  pilot  valve  applies  to  car- 
lever  control  as  well  as  to  electromagnetic  control.  It  may  be  well  to 
mention,  however,  that  the  required  increase  in  speed  cannot  always  be 
obtained  by  pilot- valve  adjustment.  Thus,  if  the  up  speed  is  too  slow 
and  the  down  speed  just  right,  then  increasing  the  up  speed  will  reduce 
the  down  speed.  If  the  down  speed  is  too  slow,  increasing  it  will  reduce 
the  up  speed.  In  cases  of  this  kind  pilot- valve  adjustment  will  do  no 
good,  as  the  cause  of  insufficient  speed  is  lack  of  power,  and  the  proper 
remedy  is  to  increase  the  pressure  in  the  pressure  tank  slightly.  It  is 
only  when  the  car  runs  faster  in  one  direction,  as  well  as  slower  than  is 
desirable  in  the  other  direction,  that  anything  can  be  done  by  pilot-valve 
adjustment. 


CHAPTER  XXI 
HORIZONTAL  HYDRAULIC  ELEVATORS 

DESCRIPTION  OF  THE  "PUSHING*'  TYPE  OF  HORIZONTAL  ELEVATORS,  DETAILS 
OF  OPERATION   AND  CONSTRUCTION  OF  VALVES  AND  PARTS 

The  main  difference  between  vertical  and  horizontal  hydraulic  ele- 
vators is  that  the  first-named  have  vertical  lifting  cylinders,  while  the 
latter  have  horizontal  cylinders.  The  valve  mechanism  of  a  vertical 
machine  can  be  used  with  perfect  success  on  a  horizontal  machine,  and 
in  fact  it  has  been  so  used  in  several  instances,  but  the  best  type  of 
horizontal  machines  have  a  valve  mechanism  of  distinctive  design; 
although  the  principle  of  operation  is  the  same  as  in  the  vertical  machine 
valve-gears  described  in  previous  chapters. 

Horizontal  hydraulic  elevators  are  divided  into  two  classes,  known  as 
the  pushing  and  pulling  types.  In  this  chapter  will  be  described  the 
Crane  pushing-type  elevator,  built  in  Chicago  by  the  Crane  Company, 
now  a  part  of  the  Otis  Elevator  Company.  This  is  one  of  the  most 
extensively  used  elevators  of  this  character.  The  general  arrangement 
is  clearly  shown  in  Fig.  98.  It  will  be  seen  that  the  rear  end  of  the 
cylinder  is  adjacent  to  the  elevator  well,  and  that  the  pressure  water 
forces  the  piston  toward  the  opposite  end,  which  results  in  pushing  the 
traveling  sheaves  away  from  the  stationary  sheaves,  thereby  drawing  the 
lifting  ropes  downward  and  lifting  the  car.  Therefore,  the  "pushing" 
type  of  elevator  derives  its  name  from  the  fact  that  the  cylinder  is  placed 
between  the  stationary  and  traveling  sheaves  and  "pushes"  them  apart 
in  order  to  raise  the  car.  The  steam  pump  draws  water  from  the  open 
tank  shown  and  forces  it  into  the  pressure  tank,  whence  it  passes  to  the 
rear  end  of  the  cylinder,  between  the  piston  and  the  back  head,  and  forces 
the  piston  forward.  On  the  return  stroke  the  water  in  the  cylinder  is 
discharged  into  the  open  tank  through  the  discharge  pipe  shown  entering 
at  one  side  of  the  tank.  The  main  valve  through  which  the  water  enters 
and  leaves  the  cylinder  is  located  at  K,  and  is  automatically  operated  by 
the  movement  of  a  pilot  valve  located  at  L,  the  latter  being  actuated  by 
the  rocking  of  the  shaft  M  through  the  movement  of  the  rods  m  m,  which 
are  connected  with  a  running-rope  system  operated  by  the  car  lever.  In 
design  the  main  valve  and  the  pilot  valve  differ  from  those  described  in 


FIG.  98 

GENERAL   ARRANGEMENT    OF    THE    VARIOUS    PARTS    OF    A   HORIZONTAL 
HYDRAULIC  ELEVATOR 


HORIZONTAL  HYDRAULIC  ELEVATORS 


133 


treating  of  vertical  elevators,  but  the  principle  of  operation  is  identical. 
An  automatic  stop  valve  is  located  at  R,  between  the  main  valve  and  the 
cylinder,  as  is  the  case  in  vertical-elevator  construction.  It  is  actuated 
by  the  mechanism  shown  at  Ar,  which  in  turn  is  set  in  motion  by  the 
movement  of  the  traveling-sheave  crosshead. 

THE  OPERATION    IN  DETAIL. 

The  operation  in  detail  can  be  more  clearly  explained  in  connection 
with  Figs.  99,  100  and  101,  the  first  being  a  side  elevation,  the  second  a 
plan  view,  and  the  third  a  vertical  cross-section  of  the  cylinder,  a  piston, 
sheaves  and  connecting  parts.  In  Fig.  99  it  will  be  seen  that  if  the  car 
lever  S  is  moved  in  either  direction  the  rods  m  m  will  rock  the  shaft  M 


FIG.  99 


FIG.   100 

and  actuate  the  pilot  valve  through  the  medium  of  the  valve-rod  L'. 
The  movement  of  the  pilot  valve  opens  or  closes  the  main  valve  K,  so 
as  to  let  water  in  or  out  of  the  cylinder,  according  to  the  direction  in 
which  the  lever  5  is  moved.  When  the  car  reaches  the  upper  end  of  the 
well,  if  the  operator  does  not  return  the  lever  .S  to  the  stop  position  the 
frame  N  will  be  carried  to  the  right  by  the  movement  of  the  cross-head, 
and  the  projecting  arm  D',  Fig.  TOO,  will  strike  a  stop  mounted  on  rod 
D",  which  is  connected  with  the  right-hand  end  of  the  frame.  This 


134 


HYDRAULIC  ELEVATORS 


movement  of  the  frame  N  will  cause  a  roller  »'  to  strike  lever  0',  which 
will  move  to  the  right  and  pull  rod  Q  in  the  same  direction;  and  this 
action  will  close  the  stop-valve  R  and  stop  the  flow  of  water  into  the  cyl- 
inder, which,  of  course,  will  stop  the  movement  of  the  piston,  and  of  the 
car.  If  the  car  is  coming  down  the  piston  will  be  moving  to  the  left,  and  if 
the  operator  does  not  return  the  lever  S  to  the  stop  position  when  the 


FIG.  101 

lower  floor  is  reached,  the  arm  D'  on  the  crosshead  D  will  strike  the 
stop  on  rod  D"  near  the  frame  N  and  carry  the  frame  to  the  left,  so  that 
arm  O  will  be  moved  by  the  roller  n,  and,  as  before,  rod  Q  will  actuate 
the  stop  valve  and  prevent  the  flow  of  water  from  the  cylinder.  The 
stop  valve  R  can  be  adjusted  to  act  at  any  time  desired,  by  means  of  the 
stops  on  the  rod  D". 

Referring  to  Fig.  101  it  will  be  seen  that  there  is  a  rubber  ring 
around  the  piston  end  of  the  plunger  E  and  a  similar  ring  in  the  cross- 
head  D,  while  attached  to  the  front  cylinder-head  G  is  a  strong  buffer 
frame  /.  If  the  car  overruns  its  normal  travel  at  either  end,  the  rubber 
ring  at  that  end  will  strike  the  buffer  /  and  prevent  the  car  going  farther 
in  that  direction.  The  adjustment  of  these  parts  should  be  such  that  the 
car  and  counterbalance  weights  cannot  strike  the  overhead  beams,  in  case 
the  automatic  stop  gets  out  of  adjustment  and  fails  to  act  in  time.  With 
proper  adjustment  there  will  be  no  contact  with  the  buffer  7  at  all,  but 
the  stretching  of  the  ropes  may  disturb  the  adjustment,  when  it  should 
be  restored  to  normal  condition  by  the  means  to  be  explained.  The 
buffer  /  and  the  back  cylinder-head  H  are  tied  together  by  means  of 
four  strong  bolts  which  extend  the  length  of  the  cylinder,  there  being 
two  on  each  side.  The  front  bolts  are  shown  at  C'  C .  The  traveling- 
sheave  crosshead  is  provided  with  rollers  which  run  on  the  tracks  //, 
their  purpose  being  to  keep  the  piston  plunger  in  line  with  the  cylinder. 
The  stationary  sheaves  at  the  back  of  the  cylinder  are  mounted  upon  and 
revolve  on  a  shaft  held  in  position  by  the  frames  h  h;  and  to  increase 
the  strength  of  the  support  these  frames  are  braced  by  wrought-iron  rods 
h'.  The  rear  end  of  the  cylinder  is  secured  to  a  heavy  foundation  T,  the 


HORIZONTAL  HYDRAULIC  ELEVATORS 


135 


weight  of  which  is  sufficient  to  overbalance  the  maximum  pull  on  the 
lifting  ropes.  The  foundation  piers  at  t,  t,  t  are  not  as  large,  being 
intended  simply  to  insure  alinement. 

THE    MAIN   AND    PILOT   VALVES. 

The  operation  of  the  main  valve  and  the  pilot  valve  may  be  under- 
stood from  Figs.  102  and  103,  the  first  a  vertical  elevation  in  section  and 
the  second  a  plan  view.  In  Fig.  102  /  and  /  are  cup  packings.  The 
pressure  water  enters  the  valve  chamber  through  the  port  /',  and  if  there 
is  no  pressure  back  of  the  piston  G  the  valve  will  move  to  the  left,  because 


JLJSU. f 


FIG.  102 


FIG.   103 

the  diameter  of  /  is  larger  than  that  of  /.  On  the  other  hand,  if  pressure 
water  is  admitted  between  the  piston  G  and  the  cylinder-head  the  valve 
will  move  to  the  right,  because  the  pressure  on  G  will  counterbalance 
that  on  7,  and  the  pressure  on  /  will  force  the  latter  to  the  right.  In 
Fig.  98  it  will  be  seen  that  the  pipe  Z  connects  the  pressure  pipe  with  the 
pilot-valve  chamber.  This  pipe  connects  with  the  port  K,  Fig.  102 ;  there- 
fore, if  the  rocking  lever  M',  Fig.  99,  is  actuated  so  as  to  move  the  lever  C, 
Fig.  102,  to  the  right,  the  pilot  valve  will  be  shifted  to  permit  the  pressure 
water  in  the  port  K  to  pass  through  port  L  to  the  back  of  piston  G. 
This  will  force  the  main  valve  to  the  right,  connecting  the  center  port  77 
with  the  discharge  port  G' '.  In  this  manner  the  water  will  be  discharged 
from  the  cylinder,  the  piston  will  move  toward  the  rear  and  the  car  will 


136 


HYDRAULIC  ELEVATORS 


descend.  If  the  lever  C  is  moved  to  the  left,  the  pilot  valve  F  will  be 
shifted  to  allow  the  water  behind  piston  G  to  run  out  through  port  L 
into  and  through  port  M  to  the  discharge  pipe. 

This  movement  of  the  main  valve  will  carry  piston  /  to  the  left  so 
that  pressure  water  from  /'  will  pass  to  and  through  H  to  the  cylinder, 
forcing  the  piston  forward  and  lifting  the  car.  The  lever  N'  is  pivoted 
at  the  point  O,  in  the  circular  frame  D,  and  its  upper  end  is  connected 
with  the  pilot- valve  stem  E' ;  consequently,  when  the  main  valve  moves 
to  the  right  it  carries  the  pilot  valve  to  the  left.  When  the  pilot  valve  is 
moved  to  the  right  by  the  car  lever,  the  main  valve  is  also  moved  to  the 
right  through  the  pressure  water  passing  from  port  K  through  port  L  to 
the  rear  end  of  the  valve  chamber ;  so,  as  soon  as  the  main  valve  begins 
to  move  it  shifts  the  pilot  valve  back  to  the  stop  position,  the  action  being 
precisely  the  same  as  in  all  the  pilot-valve  gears  previously  described. 
In  Figs.  102  and  103,  for  the  purpose  of  simplifying  the  drawings,  the 
flanged  outlets  of  ports  G',  H'  and  /  have  not  been  shown  in  their  true 
positions.  The  outlets  G'  and  /'  may  be  on  the  same  side  of  the  valve 


FIG.   104 

chamber,  or  on  opposite  sides,  according  to  which  affords  the  best  piping 
design.  The  center  outlet  H',  however,  is  always  placed  on  the  under 
side,  so  it  can  be  run  down  to  the  top  of  the  stop-motion  valve,  as  will 
be  readily  understood  from  reference  to  Fig.  99. 

THE  AUTOMATIC  STOP  VALVE. 

The  operation  of  the  automatic  stop  valve  R  is  made  clear  in  Fig. 
104,  which  is  a  vertical  section  through  the  valve  and  casing  on  a  line 
parallel  with  the  axis  of  the  cylinder.  The  construction  of  the  valve-rod 
is  shown  in  Figs.  105  and  106.  The  end  of  the  lever  a',  Fig.  99,  is  located 
within  the  square  opening  shown  in  the  end  of  the  valve-rod,  which 
allows  freedom  of  movement  for  shifting  the  valve  in  either  direction. 


HORIZONTAL  HYDRAULIC  ELEVATORS 


137 


The  weight  P'  on  the  lever  P,  Fig.  99,  is  the  medium  by  which  the  valve 
is  pulled  open  (or  on  the  left,  in  Fig.  104),  and  the  rocking  of  the  lever 
O  O'  by  the  action  of  the  frame  N  forces  the  valve  to  the  closed  position, 
or  to  the  right.  The  piston  of  the  valve  C,  which  closes  the  passage,  is 
tapered  so  as  to  gradually  stop  the  flow  of  water  and  prevent  the  suddert 
stoppage  of  the  car.  Referring  back  to  Fig.  99,  it  will  be  noted  that 
when  the  elevator  is  at  either  end  of  the  well  the  valve  R  is  closed ;  there- 
fore, unless  its  construction  permits  water  to  leak  by,  the  car  cannot  be 
started.  As  a  matter  of  fact,  the  valve  does  not  fit  perfectly,  but  leaks 
just  enough  to  permit  the  piston  to  move  slowly  in  starting  from  either 


FIG.   105 


I      | 


FIG.    i 06 


end.  This  not  only  prevents  making  a  too  sudden  start,  but  it  also 
prevents  sudden  stopping,  because  even  after  the  valve  has  been  closed 
some  water  can  pass  through  it ;  but  not  enough  to  permit  the  elevator 
to  run  at  anything  like  full  speed. 


FIG.  107 


FIG.  1 08 


The  construction  of  the  automatic  stop- valve  shifting  mechanism  is 
shown  in  Figs.  107  and  108,  the  former  being  a  side  elevation  corre- 
sponding to  Fig.  99  and  the  latter  a  top  view,  corresponding  with  Fig. 


138 


HYDRAULIC  ELEVATORS 


160.  In  these  drawings  it  can  be  seen  that  O  and  O'  are  ends  of  the 
lever  which  operates  the  stop  valve.  This  lever  is  mounted  on  a  stud 
carried  by  a  frame  bolted  to  the  side  of  the  front  cylinder-head,  the 
frame  also  serving  as  a  guide  for  the  sliding  frame  N  on  which  are 
carried  the  rollers  a  which  actuate  the  lever.  The  front  head  of  the 
stop  valve  is  shown  at  F.  The  stops  S'  S'  are  adjusted  on  the  rod  D" 
so  that  they  will  be  struck  by  the  arm  D',  projecting  from  the  side  of  the 
traveling-sheave  crosshead,  at  the  right  instant  to  bring  the  car  to  a  stop 
just  beyond  the  top  or  bottom  floor  of  the  building. 

CONSTRUCTION  OF  OTHER  PARTS. 

The  traveling-sheave  crosshead  is  shown  in  Figs.  109,  no  and  HI, 
which  are  side,  top  and  end  views,  respectively.  The  piston  plunger  is 
secured  in  A,  and  the  shaft  on  which  the  sheaves  revolve  is  held  in  the 
ends  B  B  by  means  of  set-screws.  The  lugs  C  C  are  provided  to  hold  a 
cable  guard.  The  office  of  this  guard  is  to  hold  the  cables  against  the 


FIG.  in 


sheave  surface,  in  event  of  their  becoming  slack  from  any  cause.  The 
rollers  upon  which  the  crosshead  moves  are  mounted  on  studs  fastened 
in  the  lugs  D  D.  The  rubber  buffer  already  mentioned  is  located  in  the 


HORIZONTAL  HYDRAULIC  ELEVATORS 


139 


recess  E.  To  prevent  the  piston  plunger  from  working  loose  a  pin  is 
inserted  in  the  holes  a  a.  The  operating  arm  of  the  stop-motion  mechanism 
is  bolted  to  the  seat  F.  There  are  two  seats,  one  on  each  side,  to  permit 
placing  the  stop-motion  to  suit  the  convenience. 

The  piston  is  shown  in  Fig.  112,  which  is  a  section  parallel  with  the 
axis.    As  indicated,  the  packing  is  compressed  by  means  of  a  ring  A,  by 


tightening  the  bolts  B  B.  The  buffer  ring  is  held  in  a  circular  depression 
surrounding  the  plunger,  at  C,  the  depression  being  somewhat  larger  in 
diameter  than  the  ring,  to  give  the  rubber  expansion  room  when  it  is 
acted  upon  by  the  buffer. 

The  construction  of  the  front  cylinder-head  is  shown  in  Figs.  113  and 
114,  the  first  being  an  end  view  and  the  second  a  side  elevation.  The 
head  is  secured  to  the  cylinder  flange  by  bolts  passing  through  the  holes 
a  a.  The  supporting  frame  of  'the  stop-motion  mechanism  is  bolted  to 
one  of  the  faces  B  B.  The  guides  upon  which  the  crosshead  rollers  run 
are  fastened  to  the  lugs  C  C.  These  guides  are  made  of  heavy-section 
angle  iron.  The  lugs  D  D,  located  just  below  the  lugs  C  C,  support  a 
shaft  upon  which  are  mounted  the  shell  sheaves  for  the  lifting  ropes 
running  under  the  cylinder.  The  lugs  E  E  on  the  top  of  the  head  hold  a 
shaft  on  which  are  mounted  the  small  sheaves  which  support  the  lifting 
ropes  running  over  the  top  of  the  cylinder-head.  The  large  holes  A  A  are 
for  the  long  bolts  that  hold  the  buffer  against  the  head,  and,  as  is  apparent 
in  Fig.  114,  the  part  through  which  the  holes  extend  being  turned  to 
form  a  raised  seat  to  hold  the  buffer  square  with  the  cylinder,  and 
prevent  cramping  the  piston  plunger. 

The  back  cylinder-head  is  shown  in  Figs.  115  and  116.    This  head  is 


FIG.   113 


FIG.    114 


FIG.    115 


FIG.   116 


HORIZONTAL  HYDRAULIC  ELEVATORS  141 

also  provided  with  four  large  holes  A  to  receive  the  long  bolts  that  clamp 
the  buffer  to  the  front  cylinder-head.  From  this  construction  it  is  evident 
that  whenever  the  piston  strikes  the  buffer,  the  strain  is  not  impressed 
upon  the  cylinder,  but  is  carried  by  the  bolts.  The  stop-motion  valve  is 
bolted  to  the  inlet  R,  a  port  R'  being  located  in  the  body  of  the  head. 
The  lugs  B  B  are  anchorages  to  hold  the  ends  of  the  lifting  ropes,  two 
lugs  being  provided  so  that  the  ropes  may  be  attached  at  whichever  side 
may  be  necessary. 


CHAPTER  XXII 

DESCRIPTION  OF  THE  "PULLING"  TYPE  OF  HORIZONTAL 
ELEVATOR,  SHOWING  THE  OPERATING  PRIN- 
CIPLE OF  THE  WHITTIER  MACHINE 

The  "pulling"  type  of  horizontal  hydraulic  elevator  differs  considerably 
from  the  "pushing"  type.  The  general  appearance  of  the  pulling  type  as 
made  by  the  Whittier  Machine  Company  is  illustrated  in  Fig.  117.  The 
main  operating  valve  is  at  G,  and  the  pilot  valve  is  placed  directly  above 
it,  at  /.  The  automatic  stop  valve  is  at  H  and  is  actuated  by  means  of 
stop-balls  N  mounted  on  the  rope  L.  These  stop-balls  are  moved  by 
contact  with  an  arm  attached  to  the  crosshead  which  carries  the  traveling 


_ 


FIG.  117 


WHITTIER   HORIZONTAL  ELEVATOR,   PULLING  TYPE 

sheaves  D,  and  shoes  R  on  the  crosshead  slide  within  the  side  guides. 
The  weight  P,  suspended  from  a  chain  which  travels  between  the  two 
small  guide-sheaves  located  just  below  the  valve  casing,- is  for  the  purpose 
of  bringing  the  automatic  stop  valve  to  the  central  position  as  soon  as 
the  piston  moves  away  from  either  end  of  the  cylinder. 

The  pilot  valve  is  moved  by  the  lever  K,  to  the  ends  of  which  the 
operating  ropes  that  connect  with  the  car  lever  are  attached.  The  auto- 
matic stop  valve  is  located  under  the  main  valve,  at  H,  and  is  actuated 
by  the  movement  of  rope  L,  there  being  stop-balls  N  on  the  rope  that 
are  carried  along  by  an  arm  that  projects  from  the  crosshead  and  sur- 
rounds the  rope,  as  is  clearly  shown  in  the  illustration. 

142 


THE  "PULLING"  TYPE  OF  HORIZONTAL  ELEVATOR  143 

•If  the  sheaves  shown  in  Fig.  117  are  counted,  it  will  be  found  that 
there  are  six  stationary  sheaves  E  and  five  traveling  sheaves  D.  If  there 
were  one  traveling  sheave  and  two  stationary  sheaves,  the  rope  starting 
from  the  hitching  point  A  would  run  forward  around  one  of  the  stationary 
sheaves,  thence  backward  over  the  top  and  around  the  traveling  sheave, 
then  forward  again  along  the  under  side  to  the  secondary  stationary 
sheave,  taking  a  quarter  of  a  turn  around  it,  thence  upward  to  the  top 
of  the  building.  From  this  it  will  be  seen  that  there  is  one  set  of  ropes 
passing  from  the  top  of  the  first  stationary  sheave  to  the  top  of  the 
traveling  sheave,  and  one  set  of  ropes  on  the  under  side  passing  from  the 
traveling  sheave  to  the  second  stationary  sheave;  and  according  to  the 
rule  already  given  for  determining  the  ratio  of  gearing,  this  would  be  a 
two-to-one  machine.  In  this  type  of  machine,  then,  the  gearing  ratio  can 
be  determined  by  counting  the  sheaves,  as  it  is  equal  to  the  total  number 
of  sheaves  less  one.  Therefore,  if  there  are  six  stationary  and  five  trav- 
eling sheaves  the  gearing  ratio  is  ten-to-one. 

Usually  in  the  pulling  type  of  elevator  the  ropes  are  secured  near  the 
cylinder,  but  they  can  also  be  built  with  the  ropes  hitched  at  the  forward 
end  above  the  stationary  sheaves  E.  This  construction  is  not  as  desirable, 
however,  because  it  necessitates  building  an  extension  upward  from  the 
ends  of  the  guide  frames  strong  enough  to  afford  a  safe  anchorage  for 
the  ends  of  the  ropes.  Another  objection  is  that  as  the  traveling  sheave 
moves  forward  it  carries  along  with  it  the  twist  in  the  ends  of  the  ropes, 
thus  developing  a  strong  twisting  strain  in  the  shackle-bolts.  With  the 
ends  attached  near  the  cylinder  there  is  no  such  strain,  because  the  lengths 
of  the  ropes  running  from  the  hitching  point  to  the  stationary  sheaves 
never  change. 

The  traveling-sheave  shaft  is  inclined  so  that  each  of  the  sheaves  D 
may  be  in  line  with  corresponding  sheaves  E  on  the  under  and  upper  sides. 
If  the  sheaves  were  not  so  set,  there  would  be  danger  of  the  ropes  running 
off  when  the  traveling  sheaves  are  close  to  the  stationary  sheaves.  The 
crosshead  is  designed  so  as  to  hold  the  traveling-sheave  shaft  in  the  proper 
position,  shown  in  Fig.  118.  The  trunnions  F  F  carry  the  guide-shoes  R, 
Fig.  117,  and  are  in  line  with  the  holes  B'  B'  into  which  the  piston-rods 
are  secured,  while  the  side  rods  C'  C"  fit  into  the  holes  A  A'  set  at  an 
angle  to  the  trunnions  F  F  and  the  holes  B'  B'.  The  bar  C  and  the  ends 
C  of  the  side  bars  are  larger  than  the  bar  E  and  the  ends  C" ',  because 
they  have  practically  to  take  care  of  all  the  tension,  while  the  forward 
parts  have  simply  to  hold  the  crosshead  in  position  and  carry  the  forward 
guide-shoes  R.  All  the  parts  of  the  crosshead  are  made  of  wrought 
metal,  either  steel  or  iron. 

The  main  and  the  pilot  valves  of  the  Whittier  machine  are  shown  in 


144 


HYDRAULIC  ELEVATORS 


detail  in  Figs.  119  and  120,  the  first  being  a  plan  view  and  the  second  a 
sectional  side  elevation.  Looking  at  Fig.  119,  it  will  be  seen  that  the 
operating  lever  K  is  pivoted  at  the  point  F,  so  that  when  actuated  by  the 
operating  ropes  A  A'  it  imparts  an  end  movement  to  the  pilot- valve  rod  C. 


crn 


Front  Bar 

FIG.  118 

The  ropes  A  A'  are  connected  with  the  operating  lever  in  the  car  by 
either  a  running-  or  a  standing-rope  attachment  identical  with  those  used 
for  vertical-cylinder  elevators. 

CONSTRUCTION  AND  OPERATION  OF  VALVES. 

In  Fig.  120  the  pilot- valve  rod  C  is  connected  with  the  upper  end  of 
the  lever  D,  the  latter  being  pivoted  at  G.  The  part  B  which  holds  the 
pivot  G  is  actuated  by  the  lever  K.  The  supply  pipe  is  connected  with 
the  right-hand  end  of  the  pilot- valve  chamber  through  the  pipe  E.  If  the 
rod  C  is  moved  to  the  left,  high-pressure  water  will  pass  through  the 
pilot  valve  to  the  end  /  of  the  main  valve  and  force  the  latter  to  the  left, 
thereby  connecting  the  cylinder  with  the  discharge  pipe,  when  the  water 
will  run  out  and  the  elevator  car  descend.  The  forward  movement  of 
the  main  valve  will  carry  the  lower  end  of  the  lever  D  to  the  left  and 
the  upper  end  to  the  right,  until  the  pilot  valve  is  returned  to  the  closed 


THE  "PULLING"  TYPE  OF  HORIZONTAL  ELEVATOR 


145 


position.  If  the  pilot-valve  rod  C  is  moved  to  the  right,  the  end  /  of  the 
main  valve  will  be  connected  with  the  discharge  and  the  water  will  escape, 
then  the  pressure  acting  on  the  piston  L  will  force  the  valves  to  the  right 
and  connect  the  supply  pipe  with  the  cylinder,  which  will  fill  with  water 


To  Cylinder        From  Cylinder 
FIG.    120 

from  the  pressure  tank  and  the  car  will  be  forced  upward.  The  movement 
of  the  main  valve  to  the  right  will  carry  the  lower  end  of  the  lever  D  in 
the  same  direction  and  the  upper  end  to  the  left,  and  return  the  pilot  valve 
to  the  central  position.  It  is  to  be  noted  that  the  action  of  the  valves  is 
the  same  as  in  all  pilot-valve  devices  previously  described. 


FIG.  121 


FIG.     122 


FIG.   123 

The  pilot  valve  shown  in  Fig.  120  is  provided  with  stuffing-boxes  at 
each  end  to  insure  tight  joints  with  the  valve-rod,  but  this  construction  is 
not  used  in  all  the  Whittier  elevators ;  in  some  of  them  the  pilot  valve  is 
made  as  shown  in  Fig.  121,  where  the  escape  of  water  at  the  ends  is 
prevented  by  the  use  of  cup  packings.  The  pressure  water  enters  through 


146  HYDRAULIC  ELEVATORS 

the  port  A,  the  discharge  being  through  the  port  B;  consequently,  the 
cups  are  set  so  as  to  oppose  the  pressure  which  is  exerted  in  both  direc- 
tions from  the  port  A. 

The  construction  of  the  automatic  stop  valve  of  the  type  shown  in  Fig. 
117  is  clearly  presented  in  Figs.  122  and  123,  the  former  being  a  section 
at  right  angles  to  the  axis  of  the  valve,  that  is,  parallel  with  the  axis  of 
the  lifting  cylinder,  and  the  latter  a  section  in  line  with  the  axis.  Water 
flows  through  the  valve  into  the  cylinder  from  top  to  bottom,  as  indicated 
by  the  arrows,  and  flows  out  in  the  opposite  direction.  The  valve  B  is 
rotated  by  a  carrier  A,  and  if  water  is  flowing  into  the  cylinder,  that  is,  if 
the  car  is  running  upward,  the  carrier  will  rotate  the  valve  in  a  clockwise 
direction  so  as  to  cover  the  port  C.  If  water  is  running  out  of  the 
cylinder  (the  car  running  downward)  the  carrier  A  will  rotate  the  valve 
counter-clockwise  so  as  to  cover  the  port  D;  so  that,  in  whichever 
direction  the  water  may  be  passing  through  the  valve  chamber  the  valve 
will  be  moved  over  the  port  through  which  the  flow  is  outward,  and  the 
pressure  will  force  the  valve  B  against  its  seat. 

The  valve  B  is  held  against  the  seat  normally  by  the  spring  shown, 
which  has  sufficient  tension  for  this  purpose,  but  not  enough  to  withstand 
the  pressure  of  the  water  when  acting  to  push  the  valve  B  toward  the 
center.  This  construction  is  the  same  in  principle  as  that  used  in  the 
Otis  vertical-cylinder  elevators,  and  its  object  is  to  render  it  possible  to 
start  the  elevator  on  the  return  trip  at  a  fair  rate  of  speed,  notwith- 
standing that  the  automatic  stop  valve  is  in  the  closed  position.  When 
the  elevator  is  started  on  the  return  trip  the  water  coming  to  the  valve 
chamber  from  the  opposite  direction  forces  the  valve  B  away  from  the 
seat  sufficiently  to  start  the  piston,  and  as  soon  as  the  piston  moves,  the 
valve  B,  under  the  influence  of  the  weight  P  (see  Fig.  117)  is  drawn 
away  from  the  port  to  the  central  position  in  which  it  is  shown  in  Fig.  123, 
when  the  water  has  an  unobstructed  passage  through  the  valve  chamber. 

Referring  to  Fig.  118  it  will  be  seen  that  there  are  two  piston-rods, 
b  b.  This  construction  serves  to  strengthen  the  crosshead  bar  C  by  apply- 
ing the  strain  at  points  nearer  the  side  bars,  and  in  addition  it  prevents 
the  rotation  of  the  piston,  which  would  be  undesirable,  as  it  would  increase 
the  danger  of  pulling  the  rod  out  of  the  crosshead. 


CHAPTER  XXIII 

THE  MORSE-WILLIAMS  "PULLING"  MACHINE;  CONSTRUC- 
TION AND  OPERATION  OF  THE  VALVES 

Another  design  of  the  pulling-type  elevator  is  presented  in  Figs.  124, 
125  and  126.  This  is  called  a  ' 'double-decked"  machine,  and  is  made  by 
Morse,  Williams  &  Co.,  of  Philadelphia.  Why  it  is  called  double-decked 
can  be  understood  from  the  first  illustration,  which  is  a  side  elevation 
and  shows  two  machines  placed  one  over  the  other.  In  buildings  where 
floor  space  is  limited  this  construction  is  often  adopted,  in  some  cases 
three  and  four  machines  being  installed  one  over  another.  Fig.  125  is  a 
top  view  of  Fig.  124,  and  Fig.  126  is  an  end  view  seen  from  the  right 


FIG.   125 

side.  In  these  machines  there  is  but  one  piston-rod,  as  at  B.  The 
crosshead  is  similar  to  that  in  the  Whittier  machine,  except  that  the  sides 
of  the  end  bars  are  square  with  the  side  frames,  instead  of  in  line  with 
the  traveling-sheave  shaft,  as  shown  at  /.  The  guides  F  are  set  so  that 
the  crosshead  shoes  a  slide  on  top  of  the  upper  flange,  not  between  the 
flanges. 

At  the  stationary-sheave  end  of  the  guides  there  are  shorter  guides  U 
which  carry  a  shaft  provided  with  small  rollers  b,  the  function  of  which 

147 


148 


HYDRAULIC  ELEVATORS 


is  to  support  the  ropes  running  over  the  upper  sides  of  the  sheaves.  The 
upper  machine  is  shown  with  the  traveling  sheaves  close  to  the  stationary 
sheaves,  caused  by  the  car  being  at  the  lower  floor  of  the  building.  In 
this  machine  the  supporting  rollers  b'  are  at  the  extreme  right-hand  end 
of  the  guides  U'.  In  the  lower  machine  sheaves  D  are  close  to  the 
cylinder,  as  they  will  be  when  the  elevator  car  is  at  the  top  floor.  In 
this  case  the  supporting  rollers  b  are  at  the  extreme  left-hand  end  of 
guides  U  and  midway  between  the  sheaves  D  and  E,  the  better  to  support 


w 


/%>%>•  ••••••  -^~"  .•..•r-~  ,.L-l,..V%jJgi 

L.,_l^,_., ^!_ ,  ^ L ,,„:.,„•> ., ^_^_JJL-_J 

FIG.  126 

the  ropes  at  the  central  point.  On  the  upper  machine  a  hook  /  mounted 
on  a  shaft  carried  by  the  guide  shoes  c'  engages  a  piece  e  secured  to  the 
part  /',  as  shown  in  Fig.  126,  at  the  center.  At  one  end  of  the  shaft 
which  carries  hook  /  there  is  a  lever  k.  When  the  sheaves  D'  move 
toward  the  cylinder,  the  hook  /  being  engaged  with  lever  e,  the  supporting 
rollers  b'  are  carried  along  with  the  hook  /  until  lever  k  reaches  an  inclined 
plane  m,  up  which  the  rollers  roll,  causing  the  shaft  to  be  rotated  and 
hook  /  to  be  pulled  up  out  of  the  way  of  the  lever  e,  the  rollers  being  left 
in  the  position  of  those  shown  on  the  lower  machine.  The  supporting 
roller  shaft  is  kept  in  line,  notwithstanding  that  it  is  carried  along  by 
the  part  e  acting  at  the  central  point,  by  reason  of  the  guide-shoes  C 


THE  MORSE-WILLIAMS  "PULLING"  MACHINE  149 

being  provided  with  grooves  that  fit  over  the  guides  U,  as  clearly  shown 
in  Fig.  126.  When  the  traveling  sheaves  move  forward,  the  piece  e 
engages  hook  /  when  the  latter  is  reached,  and  the  roller  shaft  is  carried 
forward  to  the  end  of  the  guides,  as  shown  at  b.  These  supporting 
rollers  relieve  the  ropes  of  considerable  strain  when  the  stroke  is  long 
and  the  traveling  sheaves  are  near  the  cylinder,  but  they  are  of  little 
service  in  short-stroke  machines.  The  movement  of  the  roller  shaft  is 
equal  to  one-half  the  stroke  of  the  machine. 

THE  STOP   AND    MAIN   VALVES. 

In  a  machine  of  the  pulling  type  the  piston  is  forced  toward  the  back 
end  of  the  cylinder  on  the  upward  motion  of  the  car.  If  the  automatic 
stop  valve  is  properly  adjusted  it  will  begin  to  close  at  the  right  time  to 
stop  the  car  even  with  the  upper  floor;  but  if  it  is  improperly  adjusted, 
the  car  is  likely  to  run  into  the  overhead  beams,  therefore  buffers  g  g, 
faced  with  rubber  cushions  h  h,  are  provided.  In  this  machine  the  auto- 
matic stop  valve  does  not  fit  perfectly,  and  if  the  main  valve  is  not  closed 
when  the  car  reaches  the  upper  floor,  the  car  will  not  stop,  but  will 
slowly  move  upward  until  the  crosshead  brings  up  against  the  buffer 
cushions  h  h.  On  the  downward  trip,  if  t,he  main  valve  is  not  closed 
when  the  car  reaches  the  lower  floor,  the  car  will  settle  gradually  until 
it  rests  on  the  bumpers,  or  the  piston  strikes  the  front  cylinder-head. 

The  main  valve  is  located  at  G  and  is  actuated  by  a  pinion  at  n  which 
meshes  with  a  rack  in  the  neck-bearing  n'.  The  automatic  stop  valve  is 
contained  within  the  casing  H  and  is  actuated  by  a  rod  connecting  with  a 
crank-pin  on  a  crank-disk  mounted  on  the  shaft  with  the  sprocket-wheel 
Q.  This  sprocket-wheel  is  rotated  by  means  of  a  sprocket  O  mounted  on 
the  shaft  with  sprocket  /,  which  latter  is  operated  by  a  chain,  the  ends  of 
which  are  affixed  to  the  ends  of  two  square  rods,  the  lower  of  which  is 
shown  at  L.  Another  chain  around  the  sprocket  P  is  connected  with  the 
opposite  ends  of  these  two  rods.  To  stop  the  movement  of  the  piston,  the 
stop  valve  is  actuated  to  the  left.  If  the  traveling  sheave  is  moving 
toward  the  cylinder  the  actuating  bar  R  attached  to  the  crosshead  will 
strike  the  stop  N  and  move  it  to  the  left,  which  will  set  up  a  counter- 
clockwise rotation  of  the  sheaves  0  and  Q,  and  this  will  move  the 
crank-pin  and  the  stop  valve  to  the  left.  If  the  traveling  sheave  is 
moving  away  from  the  cylinder,  the  lower  end  of  bar  R  will  strike  the 
stop  N  on  the  square  rod  L  and,  by  carrying  the  latter  to  the  right,  rotate 
sheaves  O  and  Q  counter-clockwise  in  the  same  direction.  The  stops  TV 
are  hook-shaped ;  they  slide  over  the  side  projections  on  bar  R,  Fig.  126, 
and  lock  with  it,  with  the  result  that  when  the  elevator  is  started  on  the 
return  trip  the  movement  of  the  crosshead  carries  the  stop  TV  with  it  and 


HYDRAULIC  ELEVATORS 


the  automatic  stop  valve  H  is  pulled  open.  When  the  elevator  is  started, 
it  moves  very  slowly  for  a  few  inches,  as  only  the  water  that  leaks  by 
the  automatic  stop  valve  is  available  to  move  it,  but  as  the  movement  of 
the  crosshead  also  operates  the  valve,  the  opening  of  the  latter  is  rapidly 
increased  and  the  car  speed  correspondingly  accelerated.  When  the  bar 
R  has  carried  the  stop  N  as  far  as  the  stop  T  the  releasing  lever  S  strikes 
the  latter,  and  the  hook  on  the  stop  N  is  raised  so  that  the  bar  R  may 
slide  by  and  leave  the  stop  N  adjoining  the  stop  T,  ready  to  be  struck 
by  the  bar  R  on  the  next  stroke.  The  actuating  stops  T  are  not  held  on 
the  rod  L,  but  on  a  rod  directly  in  front  of  it  (see  Fig.  126),  and  this  rod 
is  secured,  so  it  will  not  move  endwise,  in  the  frame  V . 

CONSTRUCTION  OF  THE  PISTON. 

The  construction  of  the  piston  is  shown  in  Fig.  124,  at  the  back  end 
of  the  lower  cylinder.     Some  of  the  other  details  are  shown  in  Figs.  127 


fcl,     '  j;       <F3K 
S-JLUr-^- "_  if^u^J 


FIG.  130 


FIG.  127 


FIG.  129 


to  135,  inclusive.  Figs.  127  and  128  show  the  front  cylinder-head  for 
the  lower  machine,  the  first  being  a  front  view,  and  the  other  a  plan  view. 
The  automatic  stop  valve  is  attached  to  the  face  B  surrounding  the  inlet 
port  A  through  which  the  water  passes  in  and  out  of  the  cylinder.  The 
cylinder  is  a  straight  piece  of  pipe  with  suitable  end  flanges  and  is  bolted 
to  the  back  of  the  head,  against  the  seat  S.  The  manner  in  which  the 
guides  F  are  held  is  clearly  shown ;  the  buffer  stands  are  fastened  to  the 
surfaces  g  g. 

Figs.  129  and  130  show  the  top  front  cylinder-head,  which  is  sub- 
stantially the  same  as  the  lower  head,  the  only  difference  being  that  the 
extensions  Y  Y  of  the  latter  are  cut  away.  Figs.  131  and  132  show  the 
top  back  cylinder-head,  which  is  materially  different  from  the  front  heads. 
This  head  is  provided  with  a  hinged  door  made  to  fit  tightly  enough  to 


THE  MORSE-WILLIAMS  "PULLING"   MACHINE 


keep  out  dust,  which  is  all  that  it  is  intended  to  accomplish.  If  there 
were  no  door  to  close  the  end  of  the  cylinder  the  machine  would  run 
perfectly,  but  the  inevitable  accumulation  of  grit  would  cause  the  lower 
side  to  wear  away  faster  than  if  protected.  This  head  also  serves  as  a 
drainage  well  to  receive  any  water  that  may  leak  by  the  piston,  and  thus 
keep  the  floor  clean.  The  dotted  line  a  a  marks  the  bottom  of  this  well, 
and  the  circular  line  b  b  is  the  seat  against  which  the  door  closes,  the 
latter  being  hinged  at  c  c. 

Fig.  133  shows  the  supporting  frame  seen  at  the  center  of  the  guide 
tracks  in  Fig.  124.    This  is  the  frame  for  the  lower  machine;  that  for  the 


K 


FIG.  132 


FIG.   133 


FIG.  131  FIG.  134 

upper  machine  is  shown  in  Fig.  134.  The  construction  of  the  stop  valve 
H  is  shown  in  Fig.  135.  The  valve  D  is  made  hollow,  so  that  there  is 
no  end  .pressure  on  it,  and  it  acts  by  covering  the  port  holes  in  the  brass 
lining  of  the  valve  casing  opposite  the  port  C  that  connects  with  the 
cylinder.  The  main  valve  is  connected  with  the  stop  valve  at  the  port  B. 

\ 


FIG. i 35 

As  will  be  seen,  the  forward  end  A  of  the  valve  D  is  cut  tapering  so  as 
to  stop  the  flow  of  water  gradually  when  it  is  closed. 

The  construction  of  the  main  valve  is  very  simple.    It  consists  of  two 
pistons  placed  far  enough  apart  to  close  the  inlet  port,  and  a  third  piston 


152 


HYDRAULIC  ELEVATORS 


located  at  the  end  next  the  piston,  which  acts  to  balance  the  end  pressure, 
the  three  pistons  being  of  the  same  size,  and  also  to  prevent  water  from 
escaping  through  the  front  of  the ,  valve  casing.  This  valve  is  moved 
toward  the  right  to  permit  the  water  in  the  cylinder  to  escape  into  the 
discharge  pipe,  and  to  the  left  to  permit  water  to  flow  into  the  cylinder 


FIG.   136  FIG.  137 

from  the  supply  pipe.  More  light  may  be  thrown  on  its  construction  by 
the  aid  of  Fig.  136,  although  this  is  not  the  same  construction  in  every 
particular,  it  being  a  design  of  more  recent  date.  In  this  figure,  if  the 
piston  D  is  removed,  it  will  leave  a  valve  like  the  main  valve  of  Fig.  124. 
Then  if  the  port  K  is  closed  and  the  pistons  B  and  C  are  moved  to  the 


THE  MORSE-WILLIAMS  "PULLING"  MACHINE 


153 


right,  water  can  flow  up  through  the  port  L  and  to  the  discharge  pipe, 
while  if  B  and  C  are  moved  to  the  left,  water  from  the  supply  pipe  can 
pass  down  through  L.  If  the  pistons  F  and  G  are  regarded  as  the  stop 
valve  D  of  Fig.  135,  it  will  be  seen  that  if  this  is  open  when  the  top 
valve  is  moved  to  the  right  the  water  will  flow  out  of  the  cylinder  and 
when  the  top  valve  is  moved  to  the  left  the  water  will  flow  into  the 
cylinder. 

OPERATION    OF    THE   VALVES. 

The  actual  operation  of  the  valves  shown  in  Fig.  136  is  decidedly 
different  from  this  explanation,  which  is  used  to  show  the  construction 
and  operation  of  the  main  valve  of  Fig.  124.  In  Fig.  136  the  lower  valves 
form  the  main  valve  and  are  moved  by  a  hand-rope  which  works  on  a 


FIG.  138 

v 

HORIZONTAL  ELEVATOR,    PULLING   TYPE 

hand-rope  sheave  indicated  by  the  circle  N.  The  top  valves  constitute 
the  automatic  stop  valve  and  are  actuated  by  mechanism  similar  to  that 
shown  in  Fig.  124,  the  sprocket-wheel  W  being  rotated  by  the  chain  M 
which  runs  ar6und  another  sprocket  P  mounted  on  the  same  shaft  as  the 
sprocket  /,  of  Fig.  124,  as  is  more  clearly  shown  in  the  top  view  of  the 
valves,  Fig.  137.  If  the  pistons  B  and  C  are  in  the  position  shown,  and 
the  main  valve  is  moved  to  the  left,  water  from  the  supply  pipe  can  flow 
through  K,  as  indicated  by  the  arrows,  and  into  the  cylinder.  If  the 
pistons  B  and  C  are  shifted  to  the  right,  so  as  to  uncover  the  port,  and 


154  HYDRAULIC  ELEVATORS 

the  main  valve  is  also  shifted  to  the  right,  then  the  water  in  the  piston 
can  escape  through  L  to  the  discharge  pipe.  The  automatic  stop  valve, 
which  is  at  the  top,  is  in  the  position  to  which  it  is  shifted  to  stop  the  car 
when  reaching  the  lower  floor  on  the  down  trip,  and  it  does  this  by  pre- 
venting the  discharge  water  in  L  from  escaping  even  if  the  main  valve  is 
open.  To  stop  the  car  on  the  up  trip,  the  pistons  B  and  C  are  moved 
over  to  the  right  until  they  cover  the  port  connecting  with  the  supply 
pipe,  and  then  the  car  will  stop,  even  if  the  main  valve  is  open,  because 
the  water  cannot  pass  beyond  the  piston  B,  which  as  will  be  noticed  is 
provided  with  double-cup  packings  so  as  to  hold  pressure  from  either 
side.  From  this  it  will  be  realized  that  the  mechanism  that  operates  this 
stop  valve  has  to  be  modified  so  as  to  move  the  valve  in  one  direction,  i.e., 
to  the  right,  to  stop  on  the  up  trip,  and  in  the  opposite  direction,  or  to  the 
left,  to  stop  on  the  down  trip. 

A  half-tone  view  of  a  Morse  &  Williams  single  machine,  equipped 
with  valves  similar  to  those  in  Fig.  136,  is  shown  in  Fig.  138.  The 
sprocket  wheel  on  the  end  of  the  pinion  shaft  of  the  main  valve  is  seen 
at  N,  and  the  sprocket  on  the  automatic  stop-valve  pinion  shaft  is  at  W. 
The  chain  can  be  seen  running  down  to  the  sprocket  P  shown  in  Fig.  136, 
which  is  just  below  the  side  frame  and  mounted  on  one  end  of  a  short 
shaft  that  carries  the  sprocket  /,  shown  in  Fig.  137,  on  its  inner  end. 
Fig.  138  also  shows  the  way  in  which  the  front  guide-supporting  frame 
is  modified  when  the  lifting  ropes  are  hitched  at  the  front  end ;  the 
shackle-bolts  being  shown  at  A.  It  will  be  noticed  that  in  this  machine 
there  are  only  five  stationary  sheaves,  yet  the  machine  is  geared  ten  to 
one.  A  little  reflection  will  show  why  one  sheave  can  be  dispensed  with. 
The  fact  that  one  sheave  less  is  required  in  a  large  measure  offsets  the 
objections  to  the  front- rope  hitch. 


CHAPTER  XXIV 

CRANE  HORIZONTAL  "PUSHING"  MACHINE;  HOW  THE 

STOP-MOTION  GETS  OUT  OF  ADJUSTMENT;  THE 

CYLINDERS  AND  OTHER  PARTS 

The  automatic  stop-valve  mechanism,  above  all  other  parts,  should  be 
kept  in  perfect  working  order  in  all  types  of  elevator,  for  if  this  is  not 
done,  and  some  other  part  should  be  disarranged,  the  car  is  likely  to  "run 
away"  and  strike  the  bumpers  violently.  Even  if  it  should  not  run  away, 
it  will  strike  the  bumpers  hard  enough  to  cause  the  passengers  discomfort 
and  alarm  if  the  operator  neglects  to  move  the  lever  to  the  stop  position 
at  the  proper  time.  It  is  very  common  practice  for  an  operator  to  depend 
upon  the  automatic  stops  to  bring  the  car  to  a  standstill  at  each  end  of 
its  travel,  consequently  if  the  adjustment  should  be  imperfect  the  car 
would  probably  strike  the  bumpers. 

The  proper  treatment  of  the  automatic-stop  mechanism  of  the  Crane 
horizontal  pushing  machine  can  be  fully  understood  by  the  aid  of  Figs. 
107  and  1 08.  It  should  be  understood  that  the  frame  N  is  moved  by 
the  motion  of  the  traveling-sheave  crosshead,  the  arm  Dr,  on  the  latter, 
striking  against  stops  fastened  to  the  operating  bar  attached  to  the  right- 
hand  end  of  the  frame  N.  As  the  movement  of  the  frame,  therefore, 
depends  on  the  position  of  the  stops  on  the  operating  bar,  it  follows  that 
these  must  be  in  such  position  that  when  the  car  is  moving  with  normal 
velocity  the  automatic  stop  will  cause  it  to  come  to  a  state  of  rest  even 
with  the  top  or  bottom  floor,  as  the  case  may  be.  The  location  of  the 
stops  is  determined  by  actual  trial,  usually  by  the  elevator  erectors,  so 
that  as  a  rule  all  that  is  necessary  afterward  is  to  keep  an  eye  on  the 
stops  and  make  sure  that  they  do  not  shift  and  are  not  likely  to. 

If  the  automatic-stop  mechanism  works  hard  there  will  be  more 
danger  of  the  stops  shifting  than  if  it  works  freely,  therefore  every  part 
that  is  liable  to  stick  should  be  examined  and  tested  frequently.  If  the 
faces  of  lever  O,  0'  become  rusty,  or  even  covered  with  dirt,  they  will 
offer  more  resistance  to  the  rollers  A,  A  than  if  bright  and  smooth,  and 
this  is  also  true  of  the  inner  faces  of  the  frame  N,  particularly  the  upper 
one.  The  pin  upon  which  the  lever  O,  O'  rocks  carries  a  roller  that  runs 
within  the  groove  of  the  frame  N,  and  the  weight  of  the  latter,  in  addition 
to  the  pull  of  the  valve  connecting-rod  A" ' ,  has  to  be  carried  by  this 


156  HYDRAULIC  ELEVATORS 

roller  whenever  the  frame  is  moved  by  the  stops  on  the  operating  rod 
to  close  the  valve.  When  the  elevator  starts  from  either  the  top  or 
bottom  floor  the  frame  N  is  moved  by  the  weight  P',  when  the  pressure 
on  the  roller  on  the  center  pin  becomes  somewhat  less  than  the  weight, 
because  the  force  required  to  move  the  valve  to  the  open  position  acts 
to  lift  the  frame  N,  the  rod  A"  having  to  push  against  the  lever  A'  in  order 
to  pull  the  valve-rod  to  the  right,  the  direction  in  which  it  should  be 
moved  to  open  the  valve.  In  this  way  more  wear  and  strain  are  brought 
to  bear  on  the  top  inner  face  of  the  frame  N  than  on  the  lower  inner 
face.  The  rollers  A,  A  should  be  kept  clean  and  well  lubricated,  other- 
wise they  are  liable  to  slide  instead  of  roll.  The  joints  of  the  valve  lever 
A'  should  also  be  kept  clean  and  free,  and  the  upper  end  should  be  pro- 
tected so  grit  will  not  get  into  it  and  cut  the  surfaces.  Each  of  these 
moving  surfaces  considered  by  itself  will  not  appreciably  affect  the  power 
required  to  move  the  stop  mechanism  if  it  should  get  rough  or  sticky  and 
run  a  little  hard,  but  several  of  them  together  will  make  a  decided 
difference. 

HOW  THE  STOP-MOTION  GETS  OUT  OF  ADJUSTMENT. 

Notwithstanding  that  the  stop-motion  is  properly  adjusted  by  the 
elevator  erectors  at  the  time  of  installation,  it  can  get  out  of  adjustment 
thereafter  through  the  wearing  away  or  displacement  of  a  part.  If  the 
car  stops  a  short  distance  beyond  the  top  and  bottom  floors,  it  is  a  sign 
that  the  stop  valve  has  become  worn  along  the  edges  that  shut  off  the 
flow  of  water,  and  to  restore  the  adjustment  so  that  the  car  will  stop 
even  with  the  floors  all  that  is  necessary  is  to  shorten  the  rod  A"  by 
means  of  the  right-and-left  coupling.  If  the  car  stops  short  of  the  top 
floor  and  runs  below  the  bottom  landing,  it  indicates  that  the  lifting  ropes 
have  stretched,  and,  while  the  proper  way  to  restore  the  adjustment  is 
by  shortening  the  ropes,  a  slight  overrunning  can  be  remedied  by  shifting 
the  stops  on  the  operating  rod  to  the  right,  so  that  the  crosshead^  will 
have  to  move  farther  from  the  cylinder  to  close  the  stop  valve  when  the 
car  is  going  upward,  and  less  near  to  the  cylinder  when  the  car  is  descend- 
ing. This  last  expedient  cannot  be  resorted  to  in  case  much  adjustment 
is  required,  however,  because  it  will  cause  the  piston  to  move  out  of  the 
cylinder  too  far  and  strike  the  buffers,  which  would  cause  the  elevator  to 
stop  even  if  the  stop  valve  were  not  entirely  closed.  In  fact,  this  adjust- 
ment cannot  be  made  unless  when  the  car  stops  at  the  top  floor  the  piston 
buffer  is  not  in  contact  with  the  stationary  buffer ;  then  the  stops  may  be 
moved  a  distance  less  than  the  clearance  between  the  buffers.  It  is 
possible  for  the  adjustment  to  become  changed  so  that  the  car  will  over- 
run the  mark  at  the  bottom  floor  only.  This  may  be  the  case  if  the  wear 
of  the  stop  valve  and  the  stretch  of  the  ropes  just  offset  each  other.  Such 


CRANE  HORIZONTAL  "PUSHING"  MACHINE 


157 


an  occurrence  is  likely  to  be  remote,  because  the  stretch  of  the  ropes  is 
almost  sure  to  be  greater  or  less.  In  any  case,  if  the  car  does  not  stop 
about  the  same  distance  below  both  landings,  it  is  because,  in  addition  to  a 
stretch  in  the  ropes,  there  is  a  leak  over  the  front  edge  of  the  stop  valve, 
and  to  correct  the  adjustment  the  ropes  and  the  rod  A"  must  be  short- 
ened. Unless  the  car  runs  far  enough  beyond  the  top  and  bottom  landings 
to  inconvenience  the  passengers,  however,  it  is  better  not  to  make  any 
adjustment. 

The  roller  C  on  which  the  frame  N  of  Fig.  107  rides,  together  with 
the  pin  C  on  which  it  is  mounted,  are  shown  in  Fig.  139.     The  pin  is 


FIG.  139 

provided  with  an  oil  cup  A  and  oil  holes  a  a',  through  which  the  surface 
with  which  the  roller  C'  contacts  is  lubricated.  The  difference  between 
the  diameter  of  the  roller  C  and  the  stud  C  is  not  very  great;  therefore, 
if  the  surface  is  permitted  to  run  dry  it  will  be  very  liable  to  cause  the 
roller  to  stick,  and  then  the  frame  will  slide  over  it,  eventually  wearing  a 
flat  spot.  This  should  be  guarded  against  carefully,  because  if  once  a  flat 
surface  is  worn  on  the  roller  it  will  be  next  to  impossible  to  keep  it 


Front  Head 
of  Cylinder, 


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V^r- 

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IN 

-A 

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°      '      .  hij     !     i:        ' 

KIOU4X4O 

revolving.  Owing  to  this  fact  it  is  advisable  not  to  lubricate  the  upper 
surface  of  the  frame  very  often,  so  that  the  sliding  friction  at  this  point 
may  be  sufficient  to  cause  the  roller  C'  to  revolve,  even  if  it  is  not  as  well 
lubricated  as  it  should  be.  The  weight  lever  P,  Fig.  107,  is  bolted  to  the 
side  of  the  cam  lever  O,  0',  and  the  latter  swings  on  the  portion  D'  of  the 
stud  C.  This  stud  is  riveted  into  a  stand,  bolted  to  the  side  of  the  front 
cylinder-head,  in  the  manner  clearly  shown  in  Fig.  140.  This  drawing 
also  shows  the  position  of  the  flange  of  the  roller  C',  which  is  between 
the  frame  TV  and  the  stand  C".  The  cam  lever  O,  O',  being  placed  out- 
side of  the  frame  TV,  serves  to  retain  the  latter  in  place.  The  cam  lever 


158  HYDRAULIC  ELEVATORS 

is  held  in  position  by  means  of  the  washer  B'  and  the  nut  B,  as  shown  in 
Fig.  139.  The  weight  P'  on  the  lever  P  returns  the  stop  valve  to  the 
open  position  each  trip  as  the  car  moves  away  from  the  landing.  By 
varying  the  position  of  the  weight  on  the  lever  the  rotative  force  can  be 
varied.  To  be  in  proper  adjustment,  the  cam  lever  should  follow  up  the 
retreating  rollers  A  A  on  the  frame  N,  so  that  the  stop  valve  may  be 
drawn  out  of  the  way  fast  enough  to  permit  the  car  to  pick  up  the 
requisite  speed  in.  starting.  If  the  cam  O,  Or  does  not  follow  up  the 
rollers  the  weight  P'  must  be  set  farther  from  the  center,  but  it  must 
not  be  set  any  farther  than  is  necessary,  because  by  so  doing  more  effort 
will  have  to  be  exerted  by  the  mechanism  when  the  valve  is  moved  to 
the  stop  position.  From  this  it  will  be  evident  that  if  the  cam  lever 
fails  to  follow  up  the  rollers  it  will  not  do  to  shift  the  weight  P'  out  to 
the  end  of  the  lever  to  make  sure  of  having  enough  moving  force,  but 
it  must  be  shifted  a  little  at  a  time,  until  the  cam  lever  follows  the  roller 
throughout  the  whole  travel;  and  then  shifted  just  a  trifle  more  so  as  to 
be  on  the  safe  side. 


CHAPTER  XXV 

CRANE  HORIZONTAL  "PUSHING"  MACHINE;  DESCRIPTION 

OF  AUTOMATIC  STOP  VALVE;  PACKING  THE 

MAIN  PISTON  AND  CYLINDERS 

The  automatic  stop  valve  of  the  Crane  machine  is  shown  in  Fig.  141, 
the  valve  casing  being  in  the  center,  the  valve  on  the  right-hand  side,  and 
the  back  head  on  the  left,  at  D.  The  valve  has  only  one  tight-fitting 
piston,  which  is  the  smallest  of  the  three  seen  at  E.  This  piston  has  a 
cup  packing  that  fits  into  a  brass  lining  fastened  into  the  front  head  of 
the  valve  casing.  To  remove  the  valve  from  the  casing  the  valve  lever 
A',  Fig.  107,  is  taken  out  by  removing  the  center  pin,  then  the  back  head 
D  is  taken  off  and  the  valve,  with  the  valve  rod,  drawn  out.  The  valve 
casing  is  placed  on  the  side  of  the  back  cylinder-head  in  the  position 


FIG.  141 

shown  in  Fig.  141,  the  flange  around  the  outlet  B  being  bolted  against 
the  cylinder-head.  The  flange  around  the  inlet  A  is  bolted  up  against 
the  under  side  of  the  main-valve  casing. 

Whenever  it  is  desirable  to  repack  the  main  valve,  the  latter  is 
removed  by  taking  off  the  back-casing  head  and  disconnecting  the  con- 
necting lever  at  the  front  end  of  the  valve-stem.  In  the  back  head  is  a 
stop-screw  (see  Fig.  102)  to  prevent  the  valve  from  moving  too  far 

159 


i6o 


HYDRAULIC  ELEVATORS 


backward  if  for  any  reason  the  pilot  valve  does  not  stop  the  flow  of 
water  at  the  proper  time,  as  for  instance  if  it  does  not  fit  tightly,  which 
is  often  the  case  with  pilot  valves  without  cup  packings.  This  stop-bolt  is 
adjusted  to  permit  the  main  valve  to  open  just  enough  to  lift  the  car 
with  the  proper  velocity  at  full  load,  and  even  if  the  operator  should  try 
to  run  it  faster  he  could  not.  If  this  stop  were  not  provided  the  car 
speed  in  most  cases  would  be  too  great,  because  as  a  rule  an  elevator 
machine  is  made  somewhat  larger  than  is  actually  necessary  to  enable  it  to 
meet  fully  the  requirements  of  the  contract  as  to  maximum  lifting 


FIG.   143 


capacity  and  speed.  When  the  machine  is  installed  the  stop  is  set,  by 
actual  trial,  to  give  the  proper  car  speed,  and  generally  the  car  lever  is 
provided  with  stops  also  set  for  this  velocity.  The  stop-bolt  does  not 
govern  the  opening  of  the  main  valve  for  the  downward  motion  of  the 
car,  this  being  controlled  by  a  stop  on  the  car  lever. 

The  valve  gear  of  the  Crane  machine  described  in  the  foregoing  is 
of  the  pilot-valve  type,  but  many  of  these  machines  are  provided  with 
simple  valve  gear,  and  the  operator  in  the  car,  by  means  of  a  hand  rope 
or  hand-wheel,  moves  the  main  valve  directly.  A  machine  of  this  type  is 
shown  in  Figs.  142  and  143,  the  first  being  a  plan  view,  and  the  second  a 
side  elevation.  The  valve  proper  is  shown  on  a  larger  scale  in  Fig.  144, 
which  shows  a  section  through  the  axis  of  two  valve  cylinders,  together 
with  an  end  view.  The  main  valve  is  located  in  the  lower  cylinder,  the 
top  valve  being  the  automatic  stop-valve.  Looking  at  the  left-hand  end 
of  the  lower  valve  rod  it  will  be  seen  that  it  terminates  in  a  rack  into 
which  meshes  a  pinion  mounted  on  a  shaft  carrying  a  hand-rope  sheave 
on  its  outer  end,  as  clearly  shown  in  the  end  view  at  A.  The  pressure 
water  enters  through  the  inlet  B  and  follows  the  path  indicated  by  the 
arrows  to  the  outlet  C,  passing  to  the  latter  when  the  piston  D  is  moved 


CRANE  HORIZONTAL  "PUSHING"  MACHINE 


161 


far  enough  to  the  left.  The  outlet  C  leads  into  the  cylinder,  therefore  if 
the  main  valve  is  moved  to  the  left  the  car  will  ascend.  If  the  main 
valve  is  moved  to  the  right  far  enough  for  the  piston  E  to  uncover  the 
outlet  C  the  flow  of  water  from  the  inlet  B  will  be  shut  off,  the  water  in 
the  cylinder  will  escape  to  the  outlet  F  and  the  car  will  run  down. 
Referring  to  Fig.  143,  it  will  be  seen  that  the  top  valve,  which  is  the 
automatic  stop,  is  controlled  by  the  movement  of  the  rod  D'f  which  is 
shifted  by  the  stop-balls  E'  and  the  shifting-arm  F'  attached  to  the 
traveling-sheave  crosshead.  If  the  rod  D'  is  shifted  to  the  right,  which 
is  the  case  when  the  car  is  running  upward,  the  upper  valve  pistons  will 
be  shifted  to  the  left,  and  from  Fig.  144  it  will  be  seen  that  this  move- 
ment will  carry  the  piston  G  over  the  inlet  port  B  and  thus  stop  the  flow 


FIG.   144 


of  pressure  water,  even  if  the  main  valve  is  not  closed.  If  the  rod  D' 
is  shifted  to  the  left,  as  it  will  be  when  the  car  is  running  downward, 
the  top  valve  will  be  shifted  to  the  right,  and  then  the  piston  H  will 
close  the  outlet  F,  so  that  water  cannot  flow  out  of  the  cylinder,  and  the 
car  will  stop  even  if  the  main  valve  is  left  open.  These  valves  can  be 
removed  from  either  end  of  the  valve  cylinders,  but  generally  it  will  be 
found  more  convenient  to  remove  them  through  the  right-hand  side,  that 
is,  on  the  side  where  the  automatic-stop  lever  is  connected. 

HOW  MAIN  PISTON   IS  PACKED. 

The  main  piston  of  the  horizontal  pushing  machine  is  packed  by 
running  the  piston  out  to  the  end  of  the  cylinder,  where  it  can  be  easily 
reached.  From  this  it  will  be  seen  that  the  packing  is  done  while  the 
car  is  at  the  top  of  the  elevator  well,  therefore  the  latter  must  be  firmly 
tied  up  to  the  overhead  beams.  To  pack  the  piston,  the  first  thing  to  do 
after  securing  the  car  to  the  overhead  beams  is  to  remove  all  the  water 
from  the  cylinder,  and  from  such  piping  as  may  extend  higher  than  the 
cylinder,  then  close  the  valve  in  the  pressure-water  pipe,  and  in  the 
discharge  as  well,  if  the  discharge  tank  is  higher  than  the  cylinder.  The 
first  step  when  the  valves  are  to  be  taken  apart  is  to  run  the  car  to  the 


1 62  HYDRAULIC  ELEVATORS 

bottom  floor,  remove  all  the  water  as  just  stated,  and  then  open  the 
casings  and  remove  the  valves.  t 

In  those  Crane  machines  which  are  provided  with  pilot-valve  gear,  a 
strainer  is  provided  to  clean  the  water  that  passes  through  the  pilot  valve. 
The  construction  of  this  strainer  is  shown  in  Fig.  145.  Its  body  is  a 
short  cylinder,  closed  at  one  end  and  provided  with  a  flange  at  the  other. 
The  actual  shape  can  be  understood  from  the  section  at  A;  the  cover  of 
the  chamber  is  shown  at  B  in  the  side  elevation  and  in  the  plan.  The 
small  disk  E  forms  the  strainer  proper  and  is  secured  in  the  cylinder  A, 
at  the  location  indicated  by  E',  being  forced  into  place.  The  two  pipes 
C  and  D,  shown  in  the  plan  view  of  the  head,  are  for  the  water  to  flow 
through,  the  inlet  being  the  pipe  D,  which  does  not  project  through  the 
strainer  disk.  The  outlet  pipe  C  projects  far  enough  through  the  head 
to  pass  through  the  large  hole  shown  in  the  strainer  disk  E.  Wire 
gauze  is  placed  over  the  disk  E.  As  the  water  enters  above  the  disk  E 
and  passes  through  the  strainer  before  it  can  reach  the  pipe  C,  when  it 
reaches  the  pilot  valve  it  is  clean,  all  the  impurities  being  retained  in  the 
cylinder  A  above  the  strainer  E;  and  to  clean  the  device  all  that  is  neces- 
sary is  to  remove  the  cover  B.  A  valve  placed  in  the  pipe  D  will  stop 
the  flow  of  water  from  the  pressure  pipe  while  the  strainer  is  being 
cleaned. 

The  rollers  which  support  the  lifting  ropes  revolve  on  a  pipe, 
capped  at  one  end  and  having  an  upturned  elbow  at  the  other,  as  shown 
in  Fig.  146.  Above  the.  elbow  is  an  oil  cup  D.  There  are  perforations 
in  the  pipe  under  the  rollers,  as  at  E.  The  construction  of  the  rollers  is 
shown  at  F  and  F'9  the  first  being  a  two-rope  and  the  other  a  four-rope 
roller.  It  will  be  seen  that  fhe  bore  is  enlarged  at  the  center,  so  as  to 
catch  the  oil.  The  oil  cup  D  can  be  made  to  swallow  sufficient  oil  to 
flood  the  pipe  A,  and  if  this  is  done  the  front  cylinder-head  and  the  floor 
under  it  will  soon  be  anything  but  neat.  By  using  a  little  judgment  these 
rollers  can  be  kept  properly  oiled  without  dripping.  If  a  rope  roller 
appears  to  run  hard  it  will  probably  be  due  to  the  clogging  of  the  oil 
hole  E,  Fig.  146,  and  by  removing  the  pipe  and  cleaning  out  the  oil  hole 
the  trouble  may  be  overcome. 

Each  set  of  sheaves  is  provided  with  rope  guards  to  hold  the  lifting 
ropes  against  the  sheaves  in  case  the  ropes  become  loosened.  The  guards 
for  the  traveling  sheaves  support  the  ropes  at  the  top  and  bottom,  and 
those  for  the  stationary  sheaves  support  them  at  the  side  as  well  as  at 
the  top  and  bottom.  These  guards  consist  of  side  frames  and  rods 
running  over  the  faces  of  the  sheaves  from  one  side  of  the  set  to  the 
other,  The  side  frames  are  secured  to  the  crosshead  in  one  case,  and  to 
the  side  frames  that  hold  the  sheaves  in  the  other  case.  The  guard  rods 


CRANE  HORIZONTAL  "PUSHING"  MACHINE 


163 


that  pass  over  the  faces  of  the  sheaves  consist  of  long  bolts,  which 
extend  through  end  holes,  and  pieces  of  gas  pipe  large  enough  to  slip 
over  the  bolts.  The  pipes  are  of  the  proper  length  to  fit  between  the 
two  frames,  the  bolts  being  longer  than  the  pipes ;  tightening  the  nuts 
causes  both  bolts  and  pipes  to  be  held  firmly  in  place. 

THE  CYLINDERS  AND  THE  PACKING. 

The  cylinders  of  horizontal  pushing  machines  are  open  at  the  front 
end  and  are,  therefore,  liable  to  become  filled  with  dust  and  grit,  which 


Q 

A 

- 

E' 

M  n 

FIG.   146 


FIG.  145 

should  not  be  permitted  to  accumulate  because  it  will  increase  the  wear 
on  the  lower  side  of  the  cylinder  and  the  piston.  The  packing  will  act 
as  a  cleaning  agent  and  keep  the  surface  apparently  clean,  but  some  of 
the  grit  will  embed  itself  in  the  packing  and  cause  it  gradually  to  grind 
the  metal  away.  If  the  machines  are  located  where  there  is  much  dust, 


164  HYDRAULIC  ELEVATORS 

a  cloth  cover  should  be  provided  to  keep  the  dust  out,  while  occasionally 
the  cylinder  should  be  swabbed  out.  This  is  not  as  easy  as  might  be 
supposed,  if  the  cylinder  is  long,  as  the  cleaning  must  be  done  when  the 
piston  is  as  far  back  in  the  cylinder  as  it  will  go,  which  brings  the  sheave 
crosshead  so  close  to  the  open  end  that  there  is  not  much  room  to  work  in. 
By  the  use  of  patience  and  with  a  little  ingenuity,  however,  the  work  can 
be  done.  A  telescopic  fishing  rod  will  greatly  facilitate  the  work;  in  its 
absence  a  bamboo  rod  can  be  made  effective. 

The  same  kind  of  packing  is  used  in  the  pistons  of  horizontal  machines 
as  in  vertical  cylinders,  that  is,  a  soft  square  packing.  It  should  be  soaked 
before  being  put  in,  if  it  is  likely  to  swell  with  water,  and  it  should  not 
be  screwed  up  too  tightly.  As  much  care,  if  not  more,  is  required  in  this 
respect  with  horizontal  cylinders,  because  they  are  of  larger  diameter 
and  therefore  subject  to  greater  strain  from  the  water  pressure  and 
from  the  tightly  compressed  packing.  These  cylinders  are  made  thicker 
on  account  of  their  greater  diameter,  but  their  strength  is  certainly  no 
greater  in  proportion  to  their  size  than  that  of  the  smaller  vertical 
cylinders.  There  is  no  excuse  for  getting  the  piston  packing  of  a 
horizontal  machine  too  tight,  because  the  side  of  the  piston  from  which 
the  packing  is  done  is  always  accessible.  This  being  the  case,  the  proper 
procedure  when  new  packing  is  put  in  is  to  tighten  it  slightly  at  first, 
then  put  on  the  water  pressure  and  make  one  trip,  if  the  packing  does 
not  leak  too  much;  then  tighten  the  follower  a  little  and  make  another 
trip;  if  still  leaky,  tighten  it  more,  and  keep  on  in  this  manner  until  it 
is  perfectly  tight.  This  cannot  be  done  with  a  vertical  cylinder.  With 
the  latter,  as  it  is  considerable  trouble  to  take  the  cylinder-head  off  to 
tighten  up  the  packing,  it  is  necessary  to  depend  upon  judgment  and  try 
to  make  the  packing  tight  enough,  but  not  too  tight,  the  first  time.  With 
both  vertical  and  horizontal  cylinders  it  is  necessary  to  be  careful  not  to 
get  the  follower  ring  screwed  up  farther  on  one  side  than  on  the  other, 
for  if  this  is  done  it  will  cramp  in  the  cylinder.  To  guard  against  this  all 
that  is  necessary  is  to  measure  from  some  finished  surface  square  with 
the  axis  at  the  end  of  the  cylinder  and  from  a  finished  surface  on  the 
follower  ring. 


CHAPTER  XXVI 

CONSTRUCTION  DETAILS  OF  THE  WHITTIER  MACHINE 

WITH  SPECIAL  REFERENCE  TO  THE 

STOP- VALVE  MECHANISM 

The  Whittier  main  operating  valve  with  pilot-valve  control  is  very 
similar  to  that  of  the  Crane  machine ;  the  slight  difference  between  them 
is  in  the  shape  of  some  of  the  minor  parts.  In  the  Whittier  valve  there 
is  an  adjusting  screw  in  the  center  of  the  back  head,  by  means  of  which 
the  car  speed  on  the  up  trip  is  regulated  so  as  to  not  exceed  a  certain 
amount,  just  as  in  the  Crane  elevator.  In  both  machines  the  valves  are 
removed  from  the  valve  casing  through  the  back  end,  after  unshipping 
the  connecting-rod  that  links  the  valve-rod  to  the  lever  which  moves  the 


FIG.   147 

pilot  valve  back  to  the  stop  position.  Between  the  pilot  valves  there  is 
practically  no  difference,  so  that  all  that  has  been  said  about  the  Crane 
valve  and  pilot  will  apply  equally  well  to  the  Whittier  apparatus. 

In  the  automatic  stop  valve  and  its  operating  mechanism  there  is  a 
considerable  difference  between  the  two  machines.  One  type  of  Whittier 
automatic  stop-valve  mechanism  is  shown  in  Fig.  147.  In  this  drawing 
the  stop  valve  is  at  H,  and  the  mechanism  for  moving  it  consists  of  the 
rod  L  upon  which  are  fastened  the  stops  N  and  N,  and  a  projecting 

165 


1 66  HYDRAULIC  ELEVATORS 

arm  M  attached  to  the  front  end  of  the  traveling-sheave  crosshead.  The 
position  of  the  arm  M  is  more  clearly  shown  in  the  plan  view.  By  means 
of  a  short  link  the  rod  L  is  connected  with  the  crank  O  on  the  shaft  of 
the  stop  valve  H,  so  that  when  the  traveling  sheaves  are  moving  toward 
the  cylinder  (the  car  going  up)  the  crank  0  is  pushed  to  the  right;  and 
when  the  sheaves  move  to  the  left,  the  crank  0  is  drawn  to  the  left. 
In  both  cases  the  weight  P  is  lifted,  the  chain  to  which  it  is  attached 
being  hung  from  the  end  of  the  crank.  As  soon  as  the  car  starts  to 
move  from  either  end  of  its  travel  the  arm  M  moves  away  from  the  stop 
N  against  which  it  may  be  pressing,  and  then  the  weight  P  will  pull  the 
crank  O  to  the  central  position;  the  chain  attached  to  the  crank  runs 
between  guide  wheels  Q  Q,  in  order  to  avoid  oscillations  of  the  crank 
before  coming  to  rest.  To  secure  satisfactory  operation  of  this  mechanism 
it  is  necessary  that  weight  P  be  heavy  enough  to  swing  the  crank  O 
around  to  the  stop  position  just  as  fast  as  the  arm  M  moves,  so  that 
the  latter  may  not  run  ahead  of  the  stop  N.  At  the  same  time,  however, 
it  is  desirable  to  make  the  weight  only  as  heavy  as  is  necessary  to  cause 
the  stop  N  to  follow  up  M  closely,  because  the  heavier  the  weight,  the 
greater  the  effort  required  to  move  the  stops  N  N,  and  the  greater  the 
liability  of  their  slipping  out  of  place  on  the  rod  L.  The  friction  of  this 
mechanism  is  very  small,  so  that  there  is  very  little  danger  of  its  becoming 
sufficient  to  cause  the  weight  to  stop,  in  its  descent,  if  it  is  made  only  a 
trifle  heavier  than  is  actually  necessary  to  do  the  work. 

STOP   VALVE  NOT  ADJUSTABLE. 

The  stop  valve  of  this  machine  is  not  adjustable  in  any  way,  so  that 
any  adjustment  that  may  be  required  must  be  done  on  the  outside 
apparatus.  If  the  car  stops  below  the  upper  floor,  it  can  be  made  to  run 
higher  by  moving  the  stop  next  to  the  cylinder  a  little  to  the  right.  If 
the  car  stops  short  of  the  lower  floor  it  can  be  made  to  run  lower  by 
moving  the  stop  next  to  the  stationary  sheaves  a  trifle  to  the  left.  It 
must  be  remembered,  however,  that  only  a  small  adjustment  can  be  made 
in  this  way,  as  it  throws  the  piston  out  of  position,  causing  it  to  run  up 
against  the  front  cylinder-head  if  the  stop  near  the  stationary  sheaves 
is  moved  too  far  to  the  left,  and  against  the  back  head  if  the  stop  near 
the  cylinder  is  moved  too  far  to  the  right.  When  the  car  is  installed,  the 
apparatus  is  properly  adjusted,  and  about  the  only  way  in  which  it  can 
get  out  of  adjustment  is  by  the  stretching  of  the  lifting  ropes,  which  is 
sure  to  occur.  The  stretching  of  the  ropes  will  cause  the  car  to  run 
below  the  lower  floor,  and  stop  short  of  the  top  floor,  and  the  proper 
way  to  restore  the  adjustment  is  by  taking  up  the  ropes,  but  sometimes 
it  is  not  convenient  to  do  this,  and  then  a  temporary  adjustment  can  be 


CONSTRUCTION  DETAILS  OF  THE  WHITTIER  MACHINE 


i67 


made  by  shifting  both  stops  N  to  the  right, .that  is,  toward  the  cylinder. 
To  determine  how  much  to  shift  them  ascertain  the  distance  by  which 
the  car  falls  short  of  the  landing,  and  then  divide  this  by  the  gear  of  the 
machine,  and  the  quotient  will  be  the  proper  distance.  Thus,  if  the  car 
falls  short  of  the  upper  landing  ten  inches,  and  runs  belew  the  bottom 
floor  a  like  amount,  and  the  gear  is  ten  to  one,  the  proper  distance  to 
shift  the  stops  is  one  inch. 

Another  arrangement  of  stop-motion  gearing  used  on  the  Whittier 
machines  is  shown  in  Fig.  148.  The  difference  between  this  and  the  one 
shown  in  Fig.  147  is  that  instead  of  the  rod  L  of  the  latter,  there  is 


FIG.   148 

substituted  a  rope  running  over  a  sheave  S  at  the  end  of  the  machine, 
and  another  sheave  attached  to  the  casing  of  the  stop  valve  H.  This 
latter  sheave  is  mounted  upon  a  shaft  which  is  geared  to  the  valve  shaft, 
so  that  when  the  rope  is  moved  by  the  arm  M  striking  either  one  of  the 
stops  N  N,  the  stop  valve  is  rotated  precisely  the  same  as  in  Fig.  147. 
The  only  advantage  of  the  rope  driving  gear  is  that  it  cannot  buckle, 
while  the  rod  L  of  Fig.  147  can  under  certain  conditions ;  for  instance,  if 
it  is  bent  slightly  in  some  accidental  manner  so  as  to  cramp  in  its  guide 
bearings,  and  therefore  refuses  to  slide  through. 

In  addition  to  what  has  been  said  in  relation  to  the  stop-gear  of  Fig. 
147,  all  that  is  necessary  with  reference  to  Fig.  148  is  to  call  attention  to 
the  fact  that  as  the  sheave  6*  is  held  in  a  frame  that  is  adjusted  to  the 
proper  position  by  means  of  the  screw  T,  it  can  work  loose  if  not  properly 
looked  after.  It  may  not  get  loose  enough  to  wabble  out  of  place,  but 
enough  so  to  twist  around,  and  interfere  with  the  proper  shifting  of  the 
stop  valve. 

MUST  BE  ANCHORED  TO  FOUNDATION. 

Horizontal  elevator  machines,  like  the  vertical  machines,  must  be 
anchored  down  to  the  foundation  or  otherwise  held  in  order  that  they 


i68 


HYDRAULIC  ELEVATORS 


may  not  be  lifted  by  the  weight  of  the  loaded  car.  The  tendency  to 
lift  the  machine,  however,  is  not  so  great  in  horizontal  as  in  vertical 
elevators,  because  the  lifting  force  is  simply  the  weight  of  the  car  and 
its  load,  less  the  weight  of  the  counterbalance.  In  vertical  machines,  the 
lifting  force  is  this  same  weight  multiplied  by  the  gear  of  the  machine,  so 
that  if  the  latter  is  four  to  one  the  lifting  force  will  be  four  times  as 
great  as  in  a  horizontal  machine.  The  bolts  that  hold  the  lifting  end  of 
the  machine  down  to  the  foundation  should  be  looked  after  from  time 
to  time  to  see  that  they  are  tight,  but  the  other  foundation  bolts  require 
little  attention.  The  difference  between  the  foundations  under  the  lifting 
end  of  the  machine  and  the  other  supports  is  shown  in  a  somewhat  exag- 
gerated form  in  Figs.  147  and  148.  In  some  buildings  of  steel-frame 
construction  it  is  common  for  the  elevators  to  be  put  in  with  founda- 
tions only  large  enough  to  hold  the  machine  in  line,  and  the  lifting  end 
of  the  machine  is  held  down  by  bracing  from  the  stationary  sheave 
bearings  up  to  the  floor  beams  of  the  floor  above.  This  construction  is 
simple  and  fully  as  good  as  the  use  of  a  heavy  holding-down  foundation. 

HAND  ROPE  ALSO  USED. 

The  Whittier  machines  are  also  made  so  as  to  be  operated  by  a  main 
valve  moved  by  the  direct  pull  of  a  hand  rope,  instead  of  by  the  action 
of  a  pilot  rope,  being  moved  either  by  hand-wheel  in  the  car,  or  by  being 


FIG.  149 

pulled  directly  by  the  operator.  The  type  of  valve  used  for  this  type  of 
operation  is  shown  in  Fig.  149,  which  is  a  section  parallel  with  the  valve 
rod.  The  hand-rope  sheave  is  mounted  on  the  shaft  A  of  the  pinion  E 
and  the  latter  meshes  into  the  rack  D  attached  to  the  end  of  the  valve 
rod.  Water  from  the  pressure  tank  enters  through  the  inlet  C,  and  if 
the  valve  is  moved  to  the  left,  it  passes  to  the  chamber  B  and  to  the 
cylinder.  If  the  valve  is  returned  to  the  position  in  which  it  is  drawn  the 
flow  of  water  will  be  stopped,  and  the  car  will  come  to  rest.  If  the  valve 
is  now  moved  farther  to  the  right,  the  water  in  the  cylinder  will  rush  out 
through  the  chamber  B  and  the  end  F  of  the  valve  casing,  and  thus  to 
the  discharge  tank.  This  valve,  it  will  be  seen,  is  substantially  the  same 
as  the  same  type  of  valve  used  with  vertical  cylinders,  and  it  is  taken 
apart,  cleaned  or  packed  in  the  same  way. 


CONSTRUCTION  DETAILS  OF  THE  WHITTIER  MACHINE 


i6g 


THE  PISTON,  SHEAVES  AND  BEARINGS  OF  THE  WHITTIER  PULLING  MACHINE. 

The  pistons  of  pulling  machines  are  slightly  different  in  design  from 
those  used  with  pushing  machines.  The  difference  is  only  that  made 
necessary  by  the  direction  in  which  the  force  is  applied.  In  pushing 
machines  the  piston  pushes  the  piston-rod  or  plunger  ahead  of  it,  but  in 


c 

-D 


FIG.  150 

pulling  machines  the  piston  pulls  the  piston-rod  along.  The  piston  used 
in  the  Whittier  pulling  machine  is  shown  in  Fig.  150,  which  gives  two 
views,  the  one  a  face  view  and  the  other  a  section  through  the  center,  in 
line  with  the  piston-rods.  These  pistons  are  easier  to  pack  than  those  of 
pushing  machines,  because  they  are  moved  to  the  back  end  of  the 
cylinder,  where  they  are  wholly  exposed,  instead  of  being  partially 
obstructed  by  a  large  piston  plunger.  The  same  kind  of  packing  is  used 
in  them  as  in  other  types  of  elevators  already  explained,  and  the  process 
of  packing  is  the  same;  that  is,  the  piston  is  forced  as  far  back  as  it 
will  go  when  the  elevator  car  is  at  the  top  of  the  building.  The  car  is 
then  securely  fastened  to  the  overhead  beams,  and  all  the  water  is  drawn 
from  the  cylinder  and  pipes,  after  which  the  packing  is  done,  As  the 


FIG.    151 

piston  is  so  accessible  the  packing  should  not  be  made  very  tight  at  first, 
but  should  be  tightened  a  little  at  a  time,  until  it  stops  leaking,  so  as  to 
run  no  risk  of  bursting  the  cylinder.  Dry  packing  that  will  swell  when 
it  gets  soaked  with  water  should  not  be  used ;  if  it  is  there  will  probably 
be  trouble. 


170  HYDRAULIC  ELEVATORS 

The  sheaves  of  horizontal  elevator  machines  are  not  easily  reached 
for  lubricating  purposes,  and  on  that  account  are  commonly  made  with 
pockets  which  hold  a  considerable  supply  of  lubricating  grease.  The 
bushing  of  the  Whittier  sheave,  in  which  are  provided  such  spaces,  is 
shown  in  Fig.  151,  which  shows  a  side  view  of  the  bushing  and  a  section 
parallel  with  the  bore.  It  will  be  seen  that  there  are  four  diagonal 
openings,  cut  through  the  bushing  at  A  A  A  A.  In  addition  to  these 
there  are  several  holes  B  B,  which  are  rilled  with  a  lubricating  grease  by 
means  of  grease  cups  set  over  each  pocket. 

All  sheaves  are  not  made  with  brass  bushings,  and  the  manufacturers 
who  use  such  bushings  do  not  always  provide  grease  pockets.  In  most 
machines  grease  cups  alone  are  used,  there  being  three  or  four  on  a 
sheave,  so  that  one  of  them  may  easily  be  reached  at  any  time.  Screw- 
cap  cups  are  preferred,  and  with  these  the  cap  is  screwed  down  a  half 
turn  or  so  each  morning  before  starting  up,  which  is  sufficient  to  keep 
the  bearing  well  lubricated. 


CHAPTER  XXVII 

OVERHEAD  SHEAVES  AND  BEARINGS;  KIND  OF  LUBRI- 
CANT BEST  SUITED  FOR  THEM ;  DISCHARGE  PIPE 
RELIEF  VALVES ;  THE  USE  OF  STRAINERS ; 
WHEN  REQUIRED 

The  overhead  sheaves  and  their  bearings  are  made  practically  the 
same  for  all  types  of  elevators.  The  general  practice  is  to  mount  the 
sheave  on  a  short  shaft  that  projects  five  or  six  inches  on  each  side,  and 
these  ends  run  in  bearings  that  are  lined  with  babbitt,  and  are  made  in 
some  cases  solid,  in  some  cases  with  a  cap,  and  in  others  in  a  more 
elaborate  manner.  The  shaft  could  be  made  fast  in  the  side  bearings, 
with  the  sheave  to  revolve  on  it,  as  is  done  in  the  traveling  sheaves,  but 
this  construction  is  not  so  desirable,  because  the  sheave  if  loose  on  the 


FIG.   152 


FIG.   153 


stud  could  in  time  wear  the  center  hole  out  of  true  so  as  to  wabble  badly. 
In  traveling  sheaves  of  horizontal  machines  this  construction  is  unavoid- 
able, and  in  vertical  machines  it  is  used  because  it  is  necessary  to  make 
the  sheave  and  frame  as  narrow  as  possible  so  as  to  be  able  to  run  in  a 
small  space;  with  the  shaft  fast  in  the  side  frames  the  structure  can  be 
made  of  considerably  less  width  than  if  side  bearings  were  provided  with 
the  sheave  fast  on  the  shaft.  A  solid  overhead-sheave  bearing  is  illus- 
trated in  Fig.  152,  which  shows  the  side  elevation  and  plan.  The  bab- 
bitted lining  of  the  bearing  is  at  A.  On  the  top  of  the  bearing  is  a 


171 


172 


HYDRAULIC  ELEVATORS 


grease  chamber  B,  covered  with  a  hinged  cap.  The  bearing  is  shown 
with  two  holes,  C  C,  for  holding-down  bolts,  this  construction  being  used 
when  the  bearings  are  supported  on  wooden  beams.  If  the  supporting 
beams  are  of  steel,  the  bearing  is  made  with  four  holes  C  for  the  holding- 
down  bolts. 

A  bearing  provided  with  a  cap  is  shown  in  Fig.  153,  which  shows  the 
side  elevation  and  plan  view.  In  this  case  the  two  halves  can  be  babbitted 
at  A  and  A',  but  as  all  the  pressure  is  on  the  lower  half  there  is  no  occasion 
to  babbitt  the  top  half,  and  it  is  better  to  leave  a  space  there  for  lubri- 
cating grease.  The  advantage  of  the  split  bearing  over  the  solid  form 
is  that  if  at  any  time  it  becomes  necessary  to  remove  the  sheave,  all  that 
is  necessary  is  to  remove  the  caps  and  lift  out  the  sheave. 

The  overhead  beams  on  which  bearings  are  held  can  spring  out  of 
line,  or  get  displaced  through  the  settling  of  the  walls  of  the  building. 


FIG.  154 

If  in  any  way  the  beams  get  displaced,  the  sheave  bearings  are  almost 
sure  to  be  thrown  out  of  line,  with  the  result  that  they  will  bind  at  one 
side  or  the  other  and  thus  run  hard,  and  possibly  heat  enough  to  cut. 
For  the  purpose  of  preventing  trouble  in  this  way  the  Otis  company 
makes  the  ball  and  socket  bearings  shown  in  Fig.  154.  The  sleeve  B  is 
turned  to  spherical  form  and  sits  in  a  spherical  seat  that  bears  at  the 
points  B'  B'.  With  this  construction  it  makes  no  difference  how  much 
the  supporting  beams  get  out  of  position,  because  the  center  part  B  will 
swing  around  on  the  surfaces  B'  B'  until  the  bearings  are  in  perfect 
alinement  with  the  shaft.  In  this  bearing  only  the  lower  half  is  babbitted, 
as  indicated  at  A.  The  upper  half  is  cored  out  to  hold  the  lubricant. 
The  clamping  bolts  E  pass  through  openings  E'  in  the  two  halves  of  the 


OVERHEAD  SHEAVES  AND  BEARINGS  173 

sleeve  B,  that  are  large  enough  to  permit  the  bearing  to  swing  more 
than  it  is  ever  likely  to  get  out  of  line  in  actual  service. 

GREASE  PREFERABLE  FOR  LUBRICATION. 

Grease  is  used  in  preference  to  oil  for  lubricating  the  overhead 
sheaves,  because  as  the  velocity  of  rotation  is  very  low,  a  hard  lubricant 
answers  every  purpose,  and  it  is  cleaner,  there  being  much  less  danger 
of  the  drip  dropping  down  on  the  elevator  car;  nevertheless,  drip  pans 
should  always  be  provided. 

DISCHARGE   PIPE  RELIEF  VALVES. 

In  every  form  of  elevator  thus  far  described,  and,  in  fact,  in  all  types 
of  hydraulic  elevators,  if  they  run  at  high  speed  it  often  happens  that 
when  the  car  is  stopped  suddenly  on  the  down  trip,  the  water  flowing 
out  of  the  valve  chamber  into  the  discharge  pipe  will  not  reduce  its 
velocity  as  fast  as  the  valve  is  closed,  the  result  being  that  the  water  is 
drawn  away  from  the  end  of  the  valve,  forming  a  vacuum  at  that  point. 
The  vacuum,  together  with  the  friction  of  the  water  flowing  through 
the  pipe,  soon  brings  the  column  of  water  to  a  state  of  rest,  and  then 
the  vacuum  draws  the  water  back,  and  in  rushing  in  to  fill  the  vacant 
space  it  strikes  a  violent  blow  against  the  under  side  of  the  valve,  which 
does  the  latter  no  good,  and  in  addition  produces  objectionable  noise. 
To  prevent  this  water  hammer,  all  high-speed  elevators  and  some  of  not 
very  high  speed  are  provided  with  a  relief  valve  connected  with  the 
discharge  pipe  just  beyond  the  end  of  the  main  valve  casing.  A  valve 
of  this  type  is  shown  in  Fig.  155.  The  body  of  the  valve  is  shown  at  A, 
and  B  is  the  cap,  a  top  view  of  which  is  shown  at  C.  This  cap  has 
openings  E,  on  each  side  of  the  center,  and  in  the  center  it  is  bored  at  D 
to  fit  the  stem  of  the  valve,  the  latter  being  shown  at  F.  To  assemble 
the  valve  the  head  Fr  is  removed  from  the  valve  stem,  and  then  the  latter 
is  slipped  through  the  center  holes  in  the  cap  B;  then  a  helical  spring  is 
slipped  over  the  valve  stem  and  compressed  in  order  to  replace  the  head 
F'.  Next  the  cap  B,  with  the  valve  in  place,  is  screwed  into  the  top  of 
the  casing  A,  the  lower  end  of  which  is  screwed  into  the  discharge  pipe. 
The  action  of  this  valve  is  as  follows : 

If  when  the  car  is  coming  down  at  a  rapid  rate,  the  main  valve  is 
suddenly  closed,  the  water  flowing  out  through  the  discharge  pipe  will 
form  a  vacuum  in  the  latter,  and  then  the  valve  will  be  drawn  in  and 
thus  opened  so  that  the  air  will  rush  in  and  reduce  the  vacuum.  Whert 
the  water  stops  flowing  and  is  drawn  back  by  the  slight  vacuum  still 
remaining,  it  will  not  strike  the  end  of  the  main  valve,  because  the  air 
drawn  in  through  the  relief  valve  will  act  as  a  cushion,  and  as  soon  as 


174 


HYDRAULIC  ELEVATORS 


it  is  compressed  to  atmospheric  pressure  will  act  to  hold  the  water  back. 

WHERE  STRAINERS  ARE  REQUIRED. 

When  hydraulic   elevators   are   installed   in   a  building   where   water 
under  sufficient  pressure  to  operate  them  can  be  drawn  from  the  street 


FIG.   155  FIG.   156 

mains  or  some  other  source,  a  fresh  supply  of  water  enters  the  cylinder 
at  each  stroke,  and,  as  it  is  liable  to  contain  many  impurities  that  could 
clog  up  the  valves  and  prevent  their  proper  action,  it  is  necessary  to 


OVERHEAD  SHEAVES  AND  BEARINGS  175 

provide  strainers.  One  of  the  many  designs  of  strainers  in  use  is  shown 
in  Fig.  156.  This  is  used  with  the  Crane  machines,  and  is  made  so  as 
to  be  inserted  in  the  supply  pipe,  preferably  with  the  strainer  grating  B 
in  a  horizontal  position.  Above  the  grating  B  a  piece  of  wire  gauze  is 
placed.  Through  the  opening  C  the  strainer  is  cleaned  out  whenever 
required. 

Very  few  elevator  installations  are  operated  with  water  drawn  from 
the  street  mains  nowadays,  as  it  is  not  possible  to  obtain  sufficient  water 
for  the  purpose  except  in  small  places  where  there  is  a  large  supply  at 
high  pressure,  and  only  a  few  elevators.  In  all  large  cities  a  pump  is 
installed  in  the  building  and  used  to  force  water  into  a  pressure  tank 
from  which  the  elevators  are  supplied.  In  such  installations  the  same 
water  is  used  over  and  over  again,  the  cylinders  discharging  into  an 
open  tank  from  which  the  pump  transfers  the  water  to  the  pressure  tank, 
the  latter  supplying  the  cylinders.  In  such  cases  it  is  evident  that  if  the 
water  when  drawn  into  the  system  is  clean,  it  can  be  kept  so ;  hence,  a 
strainer  is  not  required,  and  it  is  not  desirable  because  it  only 
adds  resistance  to  the  flow  of  water.  The  general  practice  in  such 
installations  is  for  the  makers  of  the  elevators  to  place  strainers  in 
the  supply  pipe  between  the  cylinder  and  the  pressure  tank,  when  the 
plant  is  first  started,  and  to  keep  them  in  place  for  several  weeks.  This 
is  done  in  order  to  get  out  any  impurities  that  may  be  lodged  in  any 
part  of  the  system.  These  strainers  sometimes  bring  to  light  many 
things  besides  dirt  and  chips ;  nails,  screws,  bolts  and  pocket  knives  are 
quite  common.  After  the  elevators  have  been  running  three  or  four 
weeks  the  strainers  are  removed.  These  strainers  generally  consist  of 
a  sheet  of  perforated  brass  that  is  clamped  in  one  of  the  joints  in  the 
supply  pipes,  so  that  its  removal  does  not  require  any  reconstruction  of 
the  piping.  As  water  has  to  be  supplied  to  the  system  from  time  to 
time  to  make  up  for  the  inevitable  loss  by  leakage,  it  is  advisable  to 
put  a  strainer  in  the  pipe  through  which  this  water  is  admitted,  although 
it  is  not  always  done. 


CHAPTER  XXVIII 

DISCUSSION  RELATIVE  TO  THE  DETAILS  OF  THE  MORSE 
AND  WILLIAMS  PULLING  MACHINES 

In  the  Morse  and  Williams  pulling  machine,  as  in  all  other  forms  of 
elevator,  the  automatic-stop  mechanism  should  be  most  thoroughly  under- 
stood, and  always  kept  in  perfect  order.  This  part  is  described  in  con- 
nection with  Figs.  124  and  125  in  Chapter  XXIII.  These  drawings, 
however,  do  not  show  the  construction  and  operation  of  the  mechanism 
as  well  as  might  be  desired,  and  on  that  account  the  writer  presents  here 
a  simplified  diagram  which  illustrates  the  action  of  the  several  parts 
more  clearly  than  is  possible  with  actual  working  drawings  of  the 
apparatus.  In  Fig.  157  a  side  elevation  of  the  vital  parts  of  the  stop- 
motion  mechanism  is  shown  at  A;  a  plan  view  of  A  is  shown  at  B,  and 
an  end  view  at  C.  The  several  parts  in  these  diagrammatic  illustrations 
are  lettered  the  same  as  in  Figs.  124  to  126,  in  order  to  facilitate  com- 


FIG.  157 

parative  references.  The  rods  L,  Lr  and  L"  are  of  square-section,  as 
clearly  shown  at  C,  and  to  their  ends  are  attached  sprocket  chains  that  run 
around  the  sprocket  wheels  P  and  /.  The  frames  V  and  V  support  the 
rods  L,  L'  and  also  the  rod  L" ',  which  is  directly  in  front  of  L,  as  seen 
at  B  and  also  at  C.  The  rod  L"  is  held  firmly  in  the  frames  V,  V ,  and 
its  function  is  to  hold  the  arms  T,  Tr,  which  are  fastened  upon  it  by 
means  of  suitable  screws.  The  stops  N  and  N'  are  mounted  up  L  and 
L',  respectively.  The  bar  R  is  fastened  to  the  crosshead  that  carries 

176 


DETAILS  OF  THE  MORSE  AND  WILLIAMS  PULLING  MACHINES     177 

the  traveling  sheaves,  as  shown  in  Fig.  124.  The  latch  lever  t  is  pivoted 
upon  the  stop  N,  and  is  arranged  to  slide  over  a  lateral  projection  from 
R,  as  shown  at  C,  in  Fig.  157.  The  lever  S  is  also  pivoted  upon  the 
stop  N,  and  its  upper  end  is  extended  so  as  to  engage  with  the  lower 
end  of  the  latch  t  and  be  able  to  move  the  latter  so  as  to  lift  it  out  of 
the  path  of  the  lateral  extension  on  the  bar  R. 

The  operation  of  this  stop-motion  mechanism  is  as  follows:  When 
the  elevator  car  is  at  the  lower  landing,  the  bar  R  is  at  the  right-hand 
end  of  the  rods  L,  L'  and  engaged  with  the  latch  of  ^he  lever  /.  To 
move  the  car  upward,  the  traveling  sheaves  have  to  move  to  the  left, 
and  the  bar  R  carries  the  stop  TV  with  it,  but  when  the  lever  S  reaches 
the  stationary  arm  T  it  is  prevented  from  going  farther,  and  then  its 
upper  end  swings  over  to  the  left  and  thereby  lifts  the  latch  t  and 
disengages  it  from  the  bar  R.  The  object  of  this  operation  is  to  open 
the  stop  valve  quickly  when  the  car  is  started  from  the  lower  landing. 
As  will  be  seen  by  looking  at  Fig.  124,  the  stop  valve  is  connected  with 
the  stop  mechanism  through  a  connecting-rod  that  extends  from  the  end 
of  the  valve  stem  to  a  crank-pin  on  a  disk  mounted  on  the  same  shaft 
with  the  sprocket  Q  (see  Fig.  125)  ;  hence,  the  movement  of  the  block  N 
by  its  engagement  with  the  bar  R  acts  to  move  the  stop  valve  from  the 
closed  to  the  open  position.  If  the  bar  R  did  not  carry  the  block  N 
forward,  the  stop  valve  would  remain  closed  and  on  that  account  the 
elevator  would  only  move  as  fast  as  the  water  could  pass  by  it,  no 
matter  how  much  the  main  valve  might  be  opened. 

Inasmuch  as  it  is  necessary  for  the  sprocket  O  to  rotate  a  certain 
angular  distance  in  order  to  move  the  stop  valve  from  the  closed  to  the 
wide-open  position,  it  follows  that  the  amount  of  opening  of  this  valve 
can  be  controlled  by  the  position  of  the  stationary  stop  T.  Thus  the 
position  of  the  stop  T  with  reference  to  the  block  TV  will  determine  the 
amount  of  opening  of  the  stop  valve,  and  thereby  the  maximum  speed 
at  which  the  car  can  run ;  since  this  speed  is  dependent  upon  the  volume 
of  water  that  can  pass  through  the  stop  valve,  that  is,  providing  the 
main  valve  is  opened  wide  enough  to  permit  more  water  to  pass  through 
it  than  can  pass  through  the  stop  valve.  The  stop  valve  is  set  so  as  to 
permit  the  elevator  to  run  at  the  highest  velocity  desired,  so  as  to  make 
it  impossible  for  the  operator  to  run  it  at  a  faster  speed.  If  the  stop 
valve  were  not  adjusted  so  as  to  control  the  velocity,  it  would  be  possible 
for  the  operator  to  impart  a  very  high  velocity  to  the  car  if  it  were 
empty  or  nearly  so,  and  this  velocity  might  be  high  enough  to  be  dan- 
gerous. The  position  of  the  stop  valve  only  limits  the  speed  of  the  car 
to  the  pre-determined  maximum,  but  does  not  in  any  way  interfere  with 
running  at  any  desired  lower  speed.  Any  velocity  less  than  the  maximum 


178  HYDRAULIC  ELEVATORS 

can  be  obtained  by  the  operator  by  moving  the  car  lever  so  as  to  open 
the  main  valve  to  the  proper  point. 

HOW    THE    STOP   VALVE    OPERATES    WHEN    STOPPING. 

In  the  foregoing  I  have  shown  the  operation  of  the  stop-valve 
mechanism  in  the  act  of  starting;  the  following  refers  to  the/ operation 
in  the  act  of  stopping.  Assuming  the  car  to  be  on  the  upward  trip,  with 
the  bar  R  moving  to  the  left,  the  block  N  will  be  left  resting  against  the 
right  side  of  stationary  stop  T,  and  the  bar  R  will  continue  moving  to  the 
left  as  the  car  runs  up  the  elevator  well.  When  the  car  reaches  a  point 
near  the  top  floor,  the  bar  R  will  be  in  the  position  R'  and  will  be 
carrying  the  stop  N'  to  the  left  with  it.  This  movement  of  N'  will  rotate 
the  sprocket  Q  in  a  direction  opposite  to  that  in  which  it  was  moved 
when  the  bar  R  pulled  the  block  N  along  with  it  toward  the  stop  T; 
hence,  the  stop  valve  will  be  carried  back  to  the  stop  position,  and  the 
elevator  will  be  stopped  regardless  of  whether  the  operator  moves  the 
main  valve  or  not.  Considering  this  action  of  the  bar  R  on  the  stop 
valve  through  the  movement  of  the  stop  Nf  it  is  easy  to  see  that  if  the 
stop  is  secured  to  rod  L'  too  far  to  the  right,  the  car  will  be  stopped 
before  it  reaches  the  top  floor,  while  if  it  is  set  too  far  to  the  left,  the 
car  will  run  above  the  top  floor  before  it  is  stopped  by  the  action  of  the 
automatic  stop. 

TO  SET  THE  STOP-VALVE  MECHANISM. 

From  the  foregoing  it  can  be  seen  that  to  set  the  automatic  stop-valve 
mechanism  so  that  the  car  cannot  run  beyond  a  certain  speed,  it  is 
necessary  to  shift  the  stationary  stops  T  T'  mounted  on  the  rod  L".  If 
these  stops  are  moved  toward  each  other,  the  maximum  car  speed  will 
be  increased,  and  if  moved  away  from  each  other  it  will  be  decreased. 
If  for  any  reason  it  is  desired  to  run  faster  in  one  direction  than  the 
other,  say  on  the  up  trip,  this  can  be  done  by  simply  setting  the  stops 
T  T'  in  the  proper  positions.  To  run  faster  on  the  up  trips,  the  stop  T 
is  set  farther  away  from  V,  that  is,  farther  to  the  left. 

By  properly  setting  the  stops  N  and  N'  on  the  rods  L  and  L'  the  car 
can  be  made  to  stop  automatically  and  accurately  at  the  top  and  bottom 
floors.  If  the  car  runs  beyond  the  top  floor,  set  N'  farther  to  the  right, 
and  in  the  opposite  direction  if  the  car  stops  before  reaching  the  floor. 
If  the  car  runs  below  the  lower  floor  set  the  stop  TV  to  the  left,  or  to  the 
right  if  the  car  stops  short  of  the  floor. 

In  order  that  this  mechanism  shall  operate  properly  it  is  necessary 
that  the  several  stops  remain  in  correct  adjustment.  It  can  also  be  seen 
that  as  the  bar  R  is  fastened  to  the  crosshead  of  the  machine,  if  it  is  not 
released  by  the  latches  / 1'  at  the  proper  time,  it  will  continue  to  pull 


DETAILS  OF  THE  MORSE  AND  WILLIAMS  PULLING  MACHINES     179 

Ar  or  N'  along,  and  thus  also  pull  T  or  T'  unless  these  are  secured  firmly 
enough  to  withstand  the  pull.  In  that  case  something  else  will  have  to 
give  way.  If  the  car  is  running  upward  and  the  latch  t  fails  to  release 
the  bar  R,  and  the  pull  of  the  latter  is  great  enough  to  draw  the  stop  T 
along  with  it,  the  result  will  be  that  the  sprocket  Q  will  be  rotated  until 
the  rods  L  L'  run  into  the  sprockets  /  and  P,  and  if  this  is  sufficient  to 
carry  Q  through  about  one-half  of  a  revolution,  the  stop  valve  will  be 
returned  to  the  stop  position  and  the  car  will  stop.  In  practice,  however, 
the  general  result  if  the  catch  T  fails  to  release  the  bar  R  is  that  some- 
thing about  the  mechanism  will  break;  therefore,  it  is  necessary  to  keep 
these  catches  in  proper  working  order.  It  is  also  necessary  to  keep  the 
stops  firmly  secured  so  that  the  mechanism  may  not  get  out  of  adjustment, 
and  thus  fail  to  stop  the  car  at  t*he  top  and  bottom  floors. 

To  insure  that  the  stop-valve  mechanism  shall  work  well  it  is  necessary 
that  all  the  moving  parts  be  kept  clean  and  well  oiled ;  this  is  particularly 
the  case  with  the  latch  t  and  dog  S.  The  oil  used  for  these  parts,  as 
well  as  for  the  bearings  of  rods  L  and  L'  through  the  frames  V,  V, 
should  be  of  a  kind  that  will  not  gum.  If  the  latch  t  and  the  dog  5" 
should  become  clogged  in  any  way,  they  should  be  cleaned  immediately 
with  kerosene  so  as  to  work  freely.  It  is  necessary  to  keep  all  the  parts 
in  good  condition  so  that  there  may  not  be  too  great  a  strain  on  the 
sprocket  chains  that  pass  around  the  sprocket  wheels  P  and  /.  If  one 
of  these  chains  should  break,  the  apparatus  would  become  useless,  and 
as  the  automatic  stop  valve  and  its  mechanism  constitute  the  most  valuable 
and  reliable  safety  device  attached  to  an  elevator,  they  should  never  be 
allowed  to  run  if  not  in  perfect  condition  at  every  point. 

THE  CARRIER  ROLLERS  FOR  THE  ROPE  SHEAVES. 

Another  part  of  the  mechanism  of  the  Morse  and  Williams  pulling 
machine  that  was  not  shown  as  clearly  as  might  be  desired  in  Figs.  124 
to  126  is  the  set  of  carrier  rollers  provided  to  hold  up  the  ropes  between 
the  stationary  and  the  traveling  sheaves.  These  rollers  are  mounted  in 
a  carriage  c,  Fig.  158,  that  slides  along  on  short  guides,  V.  The  con- 
struction is  such  that  when  the  car  runs  down  to  the  lower  floor  the 
crosshead  catches  the  roller  carriage,  and  on  the  next  upward  trip  carries 
it  along  with  it  until  the  piston  has  traveled  about  one-half  its  stroke. 
At  this  point  the  carriage  is  released,  and  the  rollers  remain  in  that 
position,  so  that  when  the  piston  has  moved  the  full  stroke  the  rollers 
are  about  midway  between  the  two  sets  of  sheaves.  This  construction  is 
only  used  with  very  long-stroke  machines,  but  as  these  are  common  in 
high  buildings,  it  is  necessary  to  understand  the  construction  and  operation 
of  the  mechanism. 


i8o 


HYDRAULIC  ELEVATORS 


The  upper  sketch,  Fig.  158,  shows  the  position  of  the  stationary 
sheaves  E,  and  the  traveling  sheaves  D,  when  the  car  is  at  the  lower 
floor;  and  the  lower  drawing  shows  the  position  of  the  traveling  sheaves 
when  the  carriage  supporting  the  guide  rollers  is  about  to  be  released, 
and  their  position  when  the  car  is  at  the  top  of  the  building.  The  solid- 
line  circle  D  shows  the  first-mentioned  position  of  the  traveling  sheaves, 
and  the  broken-line  circle  the  position  when  the  car  is  at  the  top  floor. 
The  flange  e  is  fastened  to  the  traveling-sheave  crosshead  frame,  and 
when  the  car  is  at  the  lower  floor  it  engages  with  the  latch  /,  on  the  end 
of  the  lever  k.  When  the  car  runs  upward,  the  traveling  sheaves  move 
to  the  left,  and  the  finger  e  pulls  the  carriage  c  along  with  it  by  means 
of  the  latch.  At  the  left-hand  end  of  the  guides  V  are  located  two 
trip-blocks  m  having  inclined  surfaces  in  the  path  of  projections  extend- 
ing from  the  side  of  the  latch  /,  and  when  the  traveling  sheave  has 


FIG.  158 

reached  the  position  shown  in  the  lower  view,  these  projections  begin  to 
slide  upward  on  the  inclined  ribs  of  the  block  m  and  thus  lift  the  latch  / 
out  of  engagement  with  the  finger  e.  As  soon  as  the  latch  is  free  from 
the  finger,  the  movement  of  carriage  c  stops  in  a  position  just  a  trifle  in 
advance  of  that  shown  in  the  lower  view,  and  the  traveling  sheave  con- 
tinues moving  to  the  end  of  the  stroke. 

It  must  be  understood  that  Fig.  158  does  not  show  the  actual  con- 
struction of  these  parts  in  the  Morse  and  Williams  machine;  these  are 
made  as  shown  in  Fig.  124,  but  Fig.  158  illustrates  the  mechanical  effects 
obtained.  The  reason  for  modifying  the  construction  is  that  the  parts 
as  actually  made,  when  presented  on  paper,  do  not  reveal  the  operation 
as  clearly  as  those  shown  in  the  simple  diagrammatic  representation. 
From  an  inspection  of  this  diagram  it  can  be  seen  that  to  keep  the 
apparatus  in  proper  running  order  it  is  necessary  not  to  permit  the  latch 
mechanism  to  get  out  of  adjustment  so  as  to  not  release  the  carriage  at 


DETAILS  OF  THE  MORSE  AND  WILLIAMS  PULLING  MACHINES     181 

the  proper  time ;  if  this  should  occur,  the  rollers  and  their  carriage  would 
be  carried  along  with  the  traveling  sheave  and  do  considerable  damage. 
If  all  the  parts  are  well  lubricated  with  an  oil  that  does  not  gum,  and 
all  joints  are  prevented  from  working  loose,  there  will  be  no  trouble. 

The  axle  that  carries  the  rope-supporting  rollers  is  made  of  extra 
strong  piping,  and  is  provided  with  an  oil  cup  at  one  end  through  which 
it  can  be  filled  so  as  to  lubricate  the  rollers.  Care  should  be  taken  to  keep 
these  well  oiled  so  that  they  may  not  stick  and  let  the  ropes  be  dragged 
over  their  stationary  edges.  The  guides  V  should  also  be  looked  at 
frequently  and  be  kept  free  from  dust  or  grit  of  any  kind,  and  well 
enough  lubricated  to  prevent  undue  friction.  The  finger  e  is  located 
midway  between  the  two  guides,  so  that  if  the  friction  of  one  of  the 
shoes  of  the  carriage  c  is  greater  than  that  of  the  other,  the  carriage  is 
liable  to  be  twisted  out  of  line,  and  possibly  enough  so  to  make  it  catch 
on  the  guides. 

The  carriage  c,  with  the  rope-supporting  rollers,  is  moved  back  from 
the  position  shown  in  the  lower  drawing  to  that  shown  in  the  upper  one 
at  each  downward  trip  of  the  car,  because  the  finger  e,  when  it  reaches 
the  latch  /  strikes  the  projection  k  back  of  the  hook  end,  and  thus  pushes 
the  carriage  back. 

THE  PISTON  OF  THE  MORSE  AND  WILLIAMS  MACHINE. 

The  piston  of  the  Morse  and  Williams  pulling  machine  is  packed  in 
practically  the  same  way  as  that  of  the  Whittier  machine,  so  that  what 
was  said  on  this  subject  in  connection  with  the  latter  machine  applies  to 
the  former.  The  construction  of  the  piston  is  fully  shown  in  Fig.  159, 
in  which  a  section  of  the  body  of  the  piston  parallel  with  the  axis  is 
shown  at  A,  and  a  top  view  at  B.  In  the  latter  the  positions  of  the 
bolts  for  pressing  down  the  stuffing-box  gland  are  shown.  A  section  of 
the  gland  is  shown  at  C.  A  cap  is  bolted  against  the  seat  surrounding 
the  opening  H,  and  is  held  central  by  fitting  into  this  opening.  This 
cap  is  for  the  purpose  of  preventing  leakage  of  any  water  that  may  escape 
through  the  hole  into  which  the  piston-rod  fits.  The  rod  is  made  with 
an  enlarged  head  that  fits  against  the  beveled  seat  at  the  end  of  the  hole 
in  F.  The  packing  is  done  by  running  the  car  to  the  top  of  the  building 
so  as  to  bring  the  piston  out  to  the  back  end  of  the  cylinder,  the  car  is 
securely  fastened  to  the  overhead  beams,  and  the  water  is  drawn  from 
the  cylinder  and  pipes  in  the  manner  previously  explained,  and  then  the 
packing  is  done. 

As  it  is  so  easy  to  get  at  the  tightening  bolts  with  this  type  of  machine 
it  is  advisable  to  not  screw  up  the  gland  ring  any  more  than  is  necessary 
to  keep  the  water  from  leaking,  then  make  a  trip,  and  if  the  piston  leaks 


182 


HYDRAULIC  ELEVATORS 


tighten  up  a  trifle  more.  It  will  not  be  much  trouble  if  you  have  to  stop 
the  car  several  times  before  you  get  the  packing  tight  enough,  and  if  this 
course  is  pursued  the  machine  will  run  much  better,  and  if  the  pressure 
used  is  barely  sufficient  to  give  the  required  speed  with  a  full  load,  the 
operation  of  the  elevator  will  be  far  more  satisfactory. 

LUBRICATION. 

The  cylinder  of  a  pulling  machine  can  be  easily  lubricated  through  the 
rear  end,  and  it  can  also  be  cleaned  out  if  at  any  time  it  should  look  as 
if  there  was  grit  in  it  that  might  cut  away  the  surface  of  the  cylinder. 
Elevators  of  all  kinds  are  generally  made  with  ample  provision  for  oiling 


FIG.   159 

the  cylinder,  the  valves  and  other  parts  inside  of  the  valve  chamber,  but 
at  the  present  time  the  most  generally  approved  method  is  by  using  lubri- 
cating compounds  that  have  come  into  use  that  are  dissolved  in  the  water. 
These  compounds  are  dropped  into  the  open  tank  and  become  mixed 
with  the  water,  and  as  the  latter  circulates  through  the  system  they  are 
deposited  on  all  the  surfaces,  and  thus  lubricate  all  the  valves,  pistons, 
rods,  etc.,  not  only  of  the  elevator  machine,  but  also  of  the  pumps.  These 
compounds  cannot  be  used  except  in  plants  where  the  same  water  is  used 
over  and  over,  but  there  are  practically  no  elevators  at  the  present  time 


DETAILS  OF  THE  MORSE  AND  WILLIAMS  PULLING  MACHINES     183 

in  which  this  is  not  done,  at  least  not  where  there  are  two  or  more 
elevators  in  use. 

The  slides  on  which  the  crosshead  shoes  run  should  not  only  be  kept 
well  oiled,  but  in  addition  should  be  examined  frequently  and  cleaned  off 
so  as  to  remove  any  grit  that  may  settle  on  them.  The  sheaves  are  as  a 


FIG.   1 60 

rule  lubricated  with  grease  fed  from  cups  provided  with  screw  caps. 
Most  sheaves  have  a  number  of  cups  so  that  one  of  them  may  easily  be 
reached  in  whatever  position  the  sheaves  may  be.  Every  morning  the 
cap  should  be  given  about  a  half  turn,  and  this  will  force  out  enough 
grease  to  last  all  day.  All  the  sheaves  should  be  attended  to,  and  as 
there  is  danger  of  having  the  arm  caught  while  reaching  in  to  the  center 


184  HYDRAULIC  ELEVATORS 

sheaves,  if  the  car  should  be  started,  the  car  should  be  run  down  to  the 
lower  floor  and  the  hand  valve  in  the  supply  pipe  closed  before  doing  this 
work.  If  the  valve  is  located  where  it  cannot  be  seen  by  the  man  working 
at  the  sheaves,  it  is  advisable  to  provide  means  to  lock  it  in  the  closed 
position  so  that  meddlesome  persons  may  not  be  able  to  open  it  and  start 
the  machine  without  his  knowledge.  All  this  may  appear  to  be  unneces- 
sarily cautious,  but  it  only  takes  a  little  time  to  do  these  things,  and  it 
is  better  to  spend  this  time  every  day  of  one's  life  than  to  have  an  arm 
mangled  just  once. 

THE  VALVE  PISTONS. 

The  valve  pistons  of  the  Morse  and  Williams  pulling  machine  are  con- 
structed substantially  the  same  as  those  used  in  the  other  machines  which 
have  been  fully  explained  in  previous  chapters.  The  only  one  that 
requires 'notice  here  is  the  stop  valve  used  in  the  type  of  machine  shown 
in  Fig.  124.  The  construction  of  the  several  parts  of  this  valve  is 
clearly  shown  in  Fig.  160.  A  sectional  view  of  the  body  of  the  valve  is 
shown  at  A;  the  clamping  head  for  the  forward  end  is  shown  in  section 
at  B;  the  back  head  also  in  section  is  shown  at  C,  and  the  leather  cup 
packings  are  shown  at  D,  D.  At  E  is  given  an  end  view  that  serves  for 
the  body  and  the  two  heads,  these  being  made  of  the  same  section.  The 
cup  packings  can  also  be  made  of  this  form  if  desired,  with  the  openings 
F  just  as  large  as  those  through  the  metal  parts,  but  it  is  better  simply  to 
punch  four  holes,  say  one-half  inch  in  diameter,  as  by  doing  so  more 
leather  is  left  to  hold  the  cup  in  shape,  and  the  opening  through  these 
holes  is  all  that  is  required.  The  object  of  these  openings  is  to  permit 
the  water  to  circulate  freely  through  the  valve  so  as  to  prevent  end 
pressure,  and  this  freedom  of  circulation  can  be  fully  obtained  through 
four  holes  of  the  size  named. 

WHY  THERE  IS  NO  PILOT  VALVE. 

It  will  be  noticed  that  in  the  Morse  and  Williams  pulling  machines 
that  have  been  shown  there  is  no  pilot  valve.  The  reason  why  this  valve 
is  not  used  is  that  a  specially  constructed  wheel-operating  device  is  pro- 
vided in  the  elevator  car,  by  means  of  which  it  is  possible  for  the  operator 
to  move  the  main  valve  with  little  effort;  therefore,  no  pilot  valve  is 
required.  The  only  reason  why  a  pilot  valve  is  used  with  any  type  of 
hydraulic  elevator  is  that  on  account  of  its  small  size  it  can  be  moved 
with  so  much  less  effort  than  the  main  valve  that  there  is  no  difficulty  in 
moving  it  by  means  of  a  lever  in  the  car,  the  end  of  which  need  travel 
through  a  distance  of  only  about  one  foot.  If  it  required  no  more  effort 
to  move  the  main  valve  than  the  pilot,  the  latter  would  not  be  used.  In 
the  Morse  and  Williams  arrangement  a  hand-wheel  about  fifteen  inches 
in  diameter  is  placed  in  the  car,  and  this  is  so  geared  with  the  main  valve 


DETAILS  OF  THE  MORSE  AND  WILLIAMS  PULLING  MACHINES     185 


that  it  has  to  be  rotated  through  nearly  one  revolution  to  open  the  valve 
fully;  therefore  the  effort  required  to  turn  the  wheel  is  greatly  reduced, 
the  distance  through  which  the  hand  is  moved  being  correspondingly 
increased.  The  operation  of  this  device  may  be  understood  by  reference 
to  Fig.  161,  which  is  a  diagrammatic  representation  of  the  system.  The 


FIG.  161 


p' 


two  stand  ropes  A,  B  are  fastened  at  the  top  of  the  elevator  well  and 
pass  around  the  sheaves  C,  D,  under  the  car,  and  thence  down  to  the  ends 
of  the  lever  P,  which  is  fixed  on  a  rock-shaft  connected  with  the  main 
valve.  The  hand-wheel  carries  on  an  extension  of  its  shaft  a  small 
sprocket  wheel  K,  and  by  rotating  the  hand-wheel  the  ropes  R  and  R'  are 
drawn  in  or  paid  out,  and  thus  the  positions  of  C  and  D  are  varied.  If 
the  wheel  is  turned  clockwise,  the  movement  of  the  ropes  R,  R'  will  be 
as  indicated  by  the  arrows  m  and  s,  and  the  sheave  D  will  be  drawn  to 
the  left  and  the  sheave  C  to  the  right,  the  rope  A  being  pulled  down,  as 


i86 


HYDRAULIC  ELEVATORS 


indicated  by  arrows  t,  t;  by  the  drawing  up  of  the  rope  B,  as  indicated 
by  arrows  n,  ri.  This  will  cause  lever  P  to  turn  its  shaft  counter- 
clockwise, and  by  the  connection  with  the  main  valve  the  latter  is  moved. 
This  arrangement  cannot  be  used  with  a  lever  in  the  car  because  it  would 
require  too  great  an  effort  to  move  the  lever.  The  hand-wheel  moves 


FIG.  162 

with  a  small  effort  because  of  the  great  leverage  over  the  valve 
mechanism;  the  hand  of  the  operator  travels  through  many  times  the 
distance  traversed  by  the  lever  P. 

In  the  diagram  all  the  sheaves  and  guide  wheels  are  drawn  so  as  to 
show  their  sides,  for  the  purpose  of  making  the  operation  perfectly  clear, 
but  their  true  position  can  be  better  judged  from  Fig.  162,  in  which  the 
sheaves  C,  D,  J  and  /  are  clearly  shown.  The  guide  sheaves  E,  F,  G,  H, 
are  not  shown  in  Fig.  162,  but  they  are  also  mounted  upon  the  car.  In 
fact,  all  the  parts  indicated  in  Fig.  161  are  mounted  upon  the  car  and 
move  with  it  except  the  standing  ropes  A,  B  and  the  lever  P. 


CHAPTER  XXIX 
HIGH  PRESSURE  HYDRAULIC  ELEVATORS 

CONSTRUCTION     AND    OPERATION    OF    THE    OTIS    VERTICAL     MACHINE;    THE 
FUNCTIONS  OF  THE  PUMPS  AND  THE  ACCUMULATOR 

All  the  elevators  discussed  in  former  chapters  belong  to  the  low-pres- 
sure class,  being  operated  by  water  under  pressures  not  over  200  pounds 
per  square  inch;  the  average  pressure  is  probably  about  100  pounds. 


Pump  to  rtturn  Pilot  Vtlve  DUchwje 
to  M»io  OUchure  8j(UQ 

FIG.   163 

Such  machines  are  very  well  suited*  to  comparatively  low  buildings,  small 
capacities  and  moderate  car  speeds.  In  very  high  buildings,  where  high 
car  velocity  is  desired  they  are  unsuitable  on  account  of  the  room  required 

187 


1 88  HYDRAULIC  ELEVATORS 

for  the  machinery  and  pipe  connections.  One  advantage  of  low-pressure 
machines  is  that  there  is  very  little  difficulty  in  keeping  the  piston,  valves 
and  other  sliding  joints  tight — so  little,  in  fact,  that  ordinary  packings 
meet  all  the  requrements  except  for  the  valves,  and  in  these  cup  packings 
are  necessary  simply  because  the  packing  has  to  slide  over  the  port 
openings. 

It  is  evident  that  if  the  pressure  of  the  water  be  increased  the  diameter 
of  the  lifting  piston  can  be  reduced  and  therefore  the  machine  can  be 
made  more  compact.  If,  however,  the  pressure  is  carried  above  200 
pounds,  the  ordinary  type  of  packing  will  not  be  satisfactory;  it  will  be 
necessary  to  substitute  cup  packings  for  it  at  practically  every  point, 
and  so  long  as  it  is  necessary  to  make  such  a  change,  it  is  advisable  to 
make  a  decided  increase  in  the  pressure  so  as  to  gain  in  a  high  degree  the 
advantages  derived  from  high  pressure.  On  this  account  high-pressure 
elevators  are  operated  with  pressures  that  average  about  seven  times  the 
average  pressure  with  low-pressure  systems.  Generally  the  high-pressure 
machines  are  operated  with  a  pressure  of  750  pounds  per  square  inch. 
The  reduction  in  the  size  of  the  machine  and  piping  that  can  be  effected 
by  using  this  pressure  is  much  greater  than  would  be  supposed  by  those 
who  have  not  investigated  the  subject.  To  give  a  general  idea  of  how 
great  the  reduction  actually  is,  suppose  a  low-pressure  elevator  has  a  cyl- 
inder 16  inches  in  diameter  and  works  with  a  pressure  of  100  pounds. 
For  such  a  machine  the  supply  pipe  would  probably  be  not  less  than  6 
inches  in  diameter.  Substitute  for  this  a  high-pressure  machine  working 
with  800  pounds  pressure  per  square  inch ;  then,  if  everything  else  remains 
unchanged,  the  area  of  the  cylinder  will  be  reduced  to  one-eighth,  and  this 
will  make  the  diameter  a  trifle  under  5^4  inches,  as  compared  with  the 
low-pressure  cylinder  of  16  inches  diameter.  This  is  not  all  the  gain  that 
can  be  made;  there  can  also  be  effected  a  great  reduction  in  the  size  of 
the  supply  pipe,  for  as  only  one-eighth  of  the  quantity  of  water  is  required 
the  size  of  the  pipe  can  be  reduced  to  the  same  degree  as  that  of  the 
cylinder,  provided  the  water  is  to  run  through  it  at  the  same  velocity. 
This  reduction  would  cut  the  pipe  down  from  6  inches  to  a  trifle  over  2 
inches  in  diameter. 

These  reductions  are  not  exactly  what  would  be  made  in  actual  prac- 
tice, because  the  frictional  loss  in  the  small  high-pressure  cylinder  would 
not  be  as  great  as  in  the  large  low-pressure  cylinder,  and  the  velocity 
of  the  water  through  the  supply  pipe  could  be  made  greater  for  the  same 
percentage  of  loss;  this  would  permit  a  further  reduction  in  the  size  of 
the  pipe.  In  practice  the  gain  in  this  direction  is  utilized  in  part  to  reduce, 
the  size  of  the  apparatus  and  in  part  to  reduce  the  loss  of  energy  in  forcing 
the  water  through  the  pipes.  As  a  result,  the  loss  of  energy  due  to  the 


HIGH  PRESSURE  HYDRAULIC  ELEVATORS 


189 


friction  of  the  water  passing  through  the  pipes,  lifting  cylinder  and  valves 
is  reduced  to  about  5  or  6  per  cent.,  whereas  in  low-pressure  machines  it 
runs  from,  say,  10  to  30  per  cent.  The  change  of  pressure  from  100  to 
700  or  800  pounds  brings  about  other  changes  in  the  construction  of  the 
machine  and  apparatus  and  also  in  the  general  arrangement  of  the  system. 
The  arrangement  of  the  various  parts  of  a  high-pressure  system  is  indi- 
cated in  the  diagram  Fig.  163.  This  diagram  shows  a  machine  geared  six; 
to  one.  The  cylinder  is  shown  at  C\  the  plunger  at  P  and  the  traveling 


FIG.  164 

sheaves  below  it ;  the  cylinder  is  inverted,  the  plunger  being  forced  down- 
ward by  the  pressure  of  the  water.  This  construction  is  used  because  the 
small  size  of  the  cylinder  makes  it  impracticable  to  use  a  piston  and  piston- 
rod,  therefore  a  solid  plunger  is  provided  and  the  pressure  acts  to  push  it 
out  of  the  cylinder.  If  the  cylinder  were  set  with  the  mouth  up,  the 
weight  of  the  car  would  tend  to  pull  the  plunger  out  of  the  cylinder. 
Machines  of  this  type  have  been  made,  but  are  not  in  use  at  the  present 


190  HYDRAULIC  ELEVATORS 

time.  In  these  machines  the  gear  was  reduced  to  two  to  one,  so  as 
to  not  have  to  add  so  much  weight  to  the  plunger ;  as  the  weight  of  the 
plunger  has  to  lift  the  car  it  must  be  sufficient  to  lift  the  maximum  load 
and  in  addition  overcome  all  the  friction. 

In  Fig.  163  the  pump  forces  water  into  the  lower  end  of  an  accumu- 
lator, from  which  a  pipe  runs  to  the  main  valve,  through  which  it  passes 
to  the  pipe  A  and  thence  to  the  lifting  cylinder.  On  the  return  stroke  the 
water  passes  out  of  the  cylinder  through  the  pipe  A  and  through  the 
upper  end  of  the  main  valve  to  the  discharge  pipe,  which  runs  up  to  a 
tank  placed  on  or  near  the  roof  of  the  building.  The  object  of  this 
arrangement  is  to  provide  a  low  pressure  to  operate  the  pilot  valve,  which 
is  shown  in  the  diagram  just  above  the  main  valve.  In  the  first  high- 
pressure  elevators  made,  the  pilot  valve  was  operated  with  water  at 
the  same  pressure  that  was  used  for  the  lifting  cylinder,  but  these  valves 
were  not  successful,  owing  to  the  fact  that  they  had  to  be  very  small  and 
the  packings  would  not  withstand  the  wear  due  to  the  pinhead  jets  of 
water  striking  them  at  terrific  velocities ;  in  addition,  the  small  holes 
through  which  the  water  passed  were  soon  enlarged  so  that  the  valve 
would  not  work  satisfactorily.  With  the  low-pressure  pilot  valve  there  is 
no  trouble.  A  small  tank  is  provided  to  receive  the  discharge  from  the 
pilot  valve  and  its  actuating  cylinder,  and  this  water  is  returned  to  the 
roof  tank  by  means  of  a  small  pump  as  shown  in  the  drawing. 

THE    ACCUMULATOR. 

The  accumulator  takes  the  place  of  the  pressure  tank  of  the  low- 
pressure  system.  A  pressure  tank  cannot  be  used  with  the  high-pressure 
system,  owing  to  the  fact  that  it  is  troublesome  and  expensive  to  pump 
air  against  a  high  pressure,  and  it  is  necessary  to  do  this  so  as  to  replenish 
the  air  that  gradually  leaks  out  of  the  pressure  tank.  Even  if  there  were 
no  difficulty  in  pumping  air  into  a  high-pressure  tank,  the  accumulator 
would  be  preferable,  because  with  it  the  pressure  depends  upon  the  weight 
on  top  of  the  plunger,  not  on  the  hight  of  the  water  in  the  cylinder.  With 
a  pressure  tank  the  pressure  drops  as  soon  as  you  begin  to  draw  water 
out,  and  it  runs  up  as  soOn  as  the  outflow  stops,  consequently  the  pressure 
is  continually  varying. 

The  actual  appearance  and  location  of  the  apparatus  of  an  Otis  high- 
pressure  vertical  elevator  are  shown  in  Fig.  164.  This  illustration  shows 
several  parts  not  represented  in  the  elementary  diagram.  The  main  pump 
is  at  A  and  at  B  is  shown  the  prime  mover,  which  in  this  case  is  an  electric 
motor,  although  in  practice  steam  power  is  almost  always  used.  The 
accumulator  is  shown  at  C  and  the  main  valve  and  pilot  valve  are  at  D. 
From  the  main  valve  the  water  passes  to  the  lifting  cylinder  through  a 


"    W 

og 

ft,    jfj 


19^  HYDRAULIC  ELEVATORS 

pipe  E,  passing  first  through  an  automatic  stop  valve  Ft  thence  through 
the  pipe  G  to  the  cylinder  H.  The  plunger  is  shown  at  /,  and  the  trav- 
eling sheaves  at  /. 

The  high-pressure  water  from  the  accumulator  reaches  the  main  valve 
through  the  pipe  K  and  is  discharged  from  the  valve  through  the  pipe  L 
which  runs  up  to  the  tank  at  the  top  of  the  building.  Through  the  pipe 
M,  the  water  returns  to  the  pump  A.  An  air  chamber  is  provided  at  Q 
to  smooth  out  any  pulsations  of  the  pump  that  its  own  air  chamber  does 
not  subdue.  The  small  pump  to  return  the  water  discharged  from  the 
pilot  valve  to  the  roof  tank  is  shown  at  N.  This  drawing  shows  all  the 
devices  generally  used,  but  several  that  are  added  for  large  plants  where 
all  the  most  approved  refinements  are  desired  are  not  shown  here. 

It  will  be  noticed  in  Fig.  164  that  the  machine  proper  of  a  vertical 
high-pressure  elevator  is  not  very  elaborate.  This,  however,  is  not  true  of 
the  horizontal  machines,  on  which  most  of  the  devices  required  for  its 
operation  are  mounted,  as  can  be  seen  in  Fig.  165,  which  shows  a  "double- 
decker."  The  main  and  pilot  valves  in  this  illustration  are  shown  at  A, 
and  at  B  is  shown  the  lever  with  which  the  ropes  that  connect  with  the 
c$r  lever  are  connected.  At  C  is  shown  the  automatic  stop  valve  which 
is  actuated  by  the  rope  D,  that  passes  around  a  sheave  E,  located  at  the 
forward  end  of  the  cylinder.  This  rope  D  is  clamped  by  the  arm  Ei  which 
is  fastened  to  a  rod  £2  that  runs  to  the  forward  end  of  the  machine  and 
carries  two  stops  E  E  and  E  E.  These  stops  are  struck  by  a  projection 
carried  on  the  traveling-sheave  crosshead  when  the  latter  approaches 
either  end  of  its  travel ;  the  action  being  the  same  as  in  the  low-pressure 
horizontal  machines  previously  described.  The  only  object  of  using  the 
rod  E2  is  to  reduce  the  length  of  the  operating  rope  D.  If  the  sheave  E 
were  placed  at  the  extreme  forward  end  of  the  machine,  and  the  rope  D 
were  run  over  it,  then  stops  could  be  placed  on  the  rope  D  in  the  usual 
way  adopted  in  other  types  of  horizontal  machines ;  but  with  this  construc- 
tion there  would  be  more  danger  of  getting  the  stop-motion  out  of  order 
by  reason  of  having  so  long  and  exposed  an  operating  rope.  The  design 
of  Fig.  165  increases  the  cost  of  construction  but  as  an  offset  to  the 
increased  expense  makes  the  machine  more  reliable  in  operation. 

At  F  is  the  automatic  stop  valve,  and  at  R  is  a  speed  regulator  to  pre- 
vent the  car  from  running  at  an  excessive  velocity  if  the  operator  should 
move  the  lever  far  enough  to  open  the  valve  wide  when  the  car  is  lightly 
loaded.  In  many  of  the  elevators  heretofore  described  the  maximum  speed 
is  determined  by  the  set  of  the  automatic  stop  valve,  but  in  this  machine, 
as  well  as  in  the  vertical-cylinder  high-pressure  machines,  the  device  R 
is  used  for  this  purpose ;  in  fact  all  the  valves  used  in  the  vertical  and  hori- 
zontal high-pressure  machines  shown  in  Figs.  164  and  165  are  the  same. 


FIG. 


FIG.  16$ 


194 

The  devices  shown  at 
pilot  valve  flows. 


HYDRAULIC  ELEVATORS 


are  strainers  through  which  the  water  for  the 


CONSTRUCTION    OF   THE    CYLINDER,    PLUNGER    AND    SHEAVES 

The  construction  of  the  cylinder,  the  plunger  and  the  sheaves  of  the 
Otis  high-pressure  vertical  machine  is  shown  in  Figs.  166  to  169.  Fig. 
166  gives  external  and  sectional  views  of  the  cylinder,  the  upper  end 
of  which  is  seen  at  A  and  the  lower  end  at  B.  To  shorten  up  the  drawing 
the  cylinder  is  broken  at  C  C.  The  plunger  is  indicated  by  D.  Above  the 
cylinder  are  shown  the  stationary  sheaves  held  between  side  frames  made 
of  channel  iron  G,  to  the  lower  end  of  which  the  cylinder  is  bolted,  as 


FIG.   167 


shown  at  G'.  The  channel  frames  G  are  bolted  to  a  rod  H  at  the  upper 
end,  and  this  is  held  between  beams  /  that  are  secured  to  the  wall  or  floor 
framing  of  the  building.  The  traveling  sheaves  are  carried  in  a  cross- 
head  attached  to  the  lower  end  F  of  the  plunger. 

The  internal  construction  of  the  cylinder  is  shown  in  the  vertical 
'section  on  the  left  side  of  the  drawing,  which  is  taken  at  right  angles  to 
the  exterior  view.  The  upper  end  of  this  drawing  shows  the  way  in 
which  the  bearings  of  the  stationary  sheaves  are  held  between  the  side 
frame  channel  beams  G  G  and  in  like  manner  the  lower  end  shows  the 
construction  of  the  cap  F  that  forms  the  end  of  the  plunger  and  the  sup- 
port for  the  traveling-sheave  frame.  This  cap  is  constructed  cup-shaped 
on  its  upper  side  to  receive  the  drip  from  the  cylinder.  The  plunger, 
it  will  be  noticed,  does  not  fit  the  cylinder  throughout  its  entire  length, 
but  only  for  a  short  distance  at  the  lower  end,  where  the  stuffing-box  is 
located.  The  cylinder  is  held  up  by  the  rod  H,  and  is  sustained  against 
side  displacement  by  means  of  one  or  more  rings  K  and  the  frame  /, 
the  construction  of  both  of  which  can  be  readily  understood  from  the 
drawings.  An  end  view  of  the  frame  /  is  shown  in  Fig.  167,  which  is  a 
section  through  the  cylinder  at  a  point  above  /  in  Fig.  166,  viewed 
downward  and  showing  a  top  view  of  the  traveling  sheaves,  which  in  a 
complete  view  of  the  elevation  would  be  seen  below  F  in  Fig.  166.  The 
outlet  M  is  the  pipe  connection  through  which  the  actuating  water  enters 
and  passes  out  of  the  cylinder.  The  pipe  itself  is  seen  at  M'  in  Fig.  167. 


196 


HYDRAULIC  ELEVATORS 


The  T-bars  /'  /'  to  which  the  frame  /  is  bolted  form  the  guides  for  the 
crosshead  of  the  traveling  sheaves,  and  the  cylinder  is  held  true  with  these 
by  means  of  the  frame  /  so  as  to  keep  the  plunger  and  the  crosshead 
guides  in  line. 

The  traveling  sheaves,  the  crosshead  and  the  guides  are  shown  in 
Figs.  168  and  169,  the  first  being  edge  and  side  elevations,  and  the  sec- 
ond a  plan  section  taken  on  line  X  X  of  the  side  elevation.  The  cross-head 
*  is  made  up  of  side  frames  Ar  consisting  of  channel  iron,  with  cross  con- 
nections between  the  sheaves  and  at  the  ends,  and  additional  cross  beams 
>V  to  which  are  fastened  the  shoes  N"  that  run  on  the  guides  /'.  The 
construction  of  the  crosshead  is  so  clearly  shown  in  the  drawings  that  a 
detailed  explanation  is  not  necessary.  To  realize  clearly  the  arrangement 


FIG.   171 

of  the  complete  cylinder  and  the  sheaves,  stationary  as  well  as  traveling, 
Fig.  168  should  be  seen  below  Fig.  166,  of  which  it  is  a  continuation. 
The  construction  is  divided  into  two  illustrations  on  account  of  the  length ; 
the  details  would  be  entirely  too  small  to  be  shown  clearly  if  the  complete 
construction  were  shown  in  one  drawing  the  length  of  these  pages. 

The  construction  of  the  cylinder  and  other  parts  of  the  horizontal 
machine  can  be  understood  from  Figs.  170  and  171,  the  former  showing 
a  side  elevation  with  the  cylinder  in  section  and  a  plan  view  of  the  whole 
machine,  the  latter  a  rear-end  view  and  a  section  at  right  angles  to  the 
cylinder  taken  on  line  A  A  of  Fig.  170.  The  cylinder  barrel  is  made  of 
wrought  iron  with  the  flanges  welded  on.  To  the  back  end  is  bolted  a 
casting  having  an  annular  chamber  from  which  a  number  of  port  holes 
open  into  the  central  bore.  This  casting  is  closed  with  a  head  held  by 
the  bolts  that  hold  the  casting  to  the  cylinder,  as  shown  in  Fig.  170.  At 
the  front  end  of  the  cylinder  is  a  casting  that  contains  the  stuffing-box; 
this  casting  is  bored  to  fit  the  plunger.  On  the  rear  end  of  the  plunger 


HIGH  PRESSURE  HYDRAULIC  ELEVATORS  197 

is  bolted  a  shoe  which  slides  on  a  brass  strip  along  the  lower  side  of  the 
cylinder  from  one  end  to  the  other.  The  object  of  this  strip  is  to  hold  the 
back  end  of  the  plunger  in  line  with  the  front  end  and  also  to  keep  the 
plunger  from  dragging  on  the  cylinder  wall  and  the  lower  side  of  the 
stuffing-box.  The  position  as  well  as  sectional  shape  of  the  wearing  strip 
is  shown  in  Fig.  171, 

In  the  plan  view  of  the  machine,  Fig.  170,  the  automatic  stop- valve 
is  shown  and  also  a  top  view  of  the  mechanism  by  which  it  is  moved. 
An  end  view  of  this  valve  is  shown  in  Fig.  171. 

Looking  at  Fig.  170  it  will  be  noticed  that  one  of  the  stationary  sheaves 
at  the  back  end  of  the  cylinder  is  larger  in  diameter  than  the  others :  this 
construction  is  used  so  as  to  b2  able  to  stack  machines  one  above  the 
other  without  setting  the  top  sheaves  back  of  the  lower  ones,  or  making 
them  of  smaller  diameter  in  order  to  afford  room  for  the  ropes  from  the 
lower  machine  to  run  up  the  elevator  well.  It  is  obvious  that  if  the 
upper  machine  is  made  with  the  large  sheave  on  the  right  side  and  the 
lower  one  has  it  on  the  left,  the  ropes  from  the  lower  machine  can  run  up 
past  the  upper  set  of  sheaves  without  striking  them,  as  they  are  of  smaller 
diameter  on  that  side  of  the  machine.  This  arrangement  is  clearly  shown 
in  Fig.  165. 


CHAPTER  XXX 

OPERATION  OF  THE  MAIN  AND  PILOT  VALVES  OF  THE 

OTIS   VERRTICAL   ELEVATOR—THE   ELECTRICAL 

CONTROL  SOMETIMES  EMPLOYED 

The  main  valve  shown  at  A  in  Fig.  165,  and  at  D  in  Fig.  164,  is  shown 
in  section  and  plan  in  Fig.  172.  The  pilot  valve  is  at  A,  and  the  main 
valve  at  C;  B  is  a  motor  cylinder,  the  piston  of  which  moves  the  main 
valve.  In  this  construction,  the  pilot  valve  is  not  much  smaller  in  diam- 
eter than  the  main  valve,  and  the  motor  piston  is  very  much  larger  than 
the  main  valve.  The  difference  in  the  proportions  of  these  parts  as 
compared  with  the  valves  described  in  connection  with  low-pressure 
machines  is  due  to  the  fact  that  in  the  high-pressure  system  the  motor 
piston  B,  is  actuated  by  low-pressure  water,  so  as  to  make  it  possible 
to  use  a  pilot  valve  of  large  enough  size  to  be  durable.  As  is  shown  in 
Fig.  164,  the  tank  into  which  the  lifting  cylinder  discharges  is  placed  high 
enough  to  give  ample  pressure  to  operate  the  motor  piston,  and  from 
this  tank  water  passes  through  the  pilot  valve  A  to  the  cylinder  B.  If  the 
motor  piston  were  operated  by  the  high-pressure  water,  the  pilot  valve 
and  its  port  holes  would  have  to  be  so  small  that  the  parts  could  not  be 
made  sufficiently  substantial.  For  this  reason  water  at  a  pressure  of  about 
80  pounds  per  square  inch  is  used  to  operate  the  motor  piston. 

It  might  be  thought  that  having  to  discharge  the  water  in  the  lifting 
cylinder  against  a  back  pressure  of  80  pounds  would  cause  considerable 
loss  and  make  the  high-pressure  system  objectionable  on  the  score  of  low 
efficiency,  but  this  is  not  the  case  because  the  main  pump  draws  water 
from  the  same  discharge  tank;  therefore,  the  back  pressure  against  the 
lifting  cylinder  acts  to  help  the  pump,  so  that  in  reality  the  work  the 
pump  has  to  do  is  to  force  water  against  a  pressure  equal  to  the  differ- 
ence between  the  pressure  of  the  accumulator  and  that  of  the  discharge 
tank.  The  net  result  is  that  if  the  accumulator  pressure  is  750  pounds, 
and  that  of  the  discharge  tank  is  80  pounds,  the  actual  pressure  against 
which  the  pump  acts  is  750  —  80  =  670  pounds,  and  the  pressure  that  acts 
in  the  lifting  cylinder  to  raise  the  elevator  car  is  670  pounds,  not  taking 
into  account  the  losses  due  to  friction  of  the  water  through  the  pipes 
and  valves  on  its  way  from  the  accumulator  to  the  cylinder. 

OPERATION  OF  MAIN  AND  PILOT  VALVES. 

The  operation  of  the  main  and  pilot  valve  of  Fig.  172  is  as  follows : 
If  the  operator  desires  to  run  the  car  upward  he  moves  the  car  lever 

198 


OPERATION  OF  THE  MAIN  AND  PILOT  VALVES 


199 


so  as  to  pull  up  the  rope  N'  on  the  right  side,  thus  tilting  the  rock  lever 
N  in  a  counter-clockwise  direction.  The  levers  N  and  L  are  secured 
to  the  shaft  P;  hence,  the  end  of  L  will  move  down  and  through  the  con- 
necting-rod L'  will  pull  down  the  lever  L" ' ;  and  the  latter,  through  M, 
will  depress  the  pilot  valve.  The  center  pipe  £j  is  connected  with  the 


FIG.  172 

upper  discharge  tank;  hence,  water  will  flow  in  and  through  the  lower 
end  of  the  pilot-valve  chamber,  pass  to  the  lower  end  of  the  motor-piston 
cylinder  B,  and  raise  the  piston,  the  water  above  the  latter  passing  out 
into  the  pilot-valve  chamber  above  the  valve,  and  thence  to  the  pipe  D. 
As  the  motor  piston-rod  is  connected  at  both  ends  by  arms  /  /  with  the 


200 


HYDRAULIC  ELEVATORS 


ends  of  the  main  valve  C,  the  upward  movement  of  the  piston  will  lift 
the  main  valve,  and  then  the  water  from  the  accumulator  coming  through 
the  pipe  /  will  pass  into  the  center  of  the  main  valve  through  the  port  S. 
The  ports  Q  will  be  above  the  packing  R,  so  that  the  water  will  pass 
out  into  the  central  pipe  H  and  thence  to  the  lifting-cylinder,  and  by 
pushing  the  plunger  out  of  the  latter  will  lift  the  elevator  car.  If  the 


FIG.  173 

rock  lever  N  is  tilted  in  the  opposite  direction,  the  pilot  valve  will  be 
raised,  and  then  water  will  pass  to  the  upper  end  of  the  motor  cylinder 
and  depress  the  piston,  thus  moving  the  main  valve  down  so  that  the 
water  in  the  lifting  cylinder  may  escape  through  the  ports  Q'  into  the 
upper  end  of  the  main  valve  and  thence  through  the  ports  S'  to  the  upper 
discharge  pipe  G;  from  there  it  passes  to  the  discharge  tank  near  the  top 
of  the  building. 


OPERATION  OF  THE  MAIN  AND  PILOT  VALVES 


201 


Upon  examining  this  valve-gear  it  will  be  found  that  as  soon  as  the 
main  valve  moves  it  acts  to  return  the  pilot  valve  to  the  central  position ; 
thus,  if  the  pilot  valve  is  raised,  the  main  valve  will  immediately  there- 
after start  to  move  upward,  and  then  the  lever  L" ' ,  which  is  pivoted  on 
the  arm  /,  will  start  to  draw  up  the  link  M,  thereby  moving  the  pilot 
valve  toward  the  stop  position.  When  it  has  lifted  the  pilot  valve  to 


FIG.  174 

this  position,  the  main  valve  will  move,  no  farther,  so  that  the  extent  of 
the  opening  of  the  main  valve  will  depend  upon  the  distance  through 
which  lever  N  is  moved.  This  action,  as  will  be  noticed,  is  precisely  the 
same  as  that  of  the  pilot  valves  of  the  low-pressure  systems,  so  that  the 
principle  of  operation  of  the  valve-gear  of  Fig.  172  is  the  same  as  that  of 
those  used  in  all  other  hydraulic  elevators  operated  by  pilot  valves,  the 
only  differences  being  in  the  details  of  construction.'  These  are  greater 
than  the  difference  between  different  designs  of  low-pressure  valves  owing 


2O2  HYDRAULIC  ELEVATORS 

to  the  fact  that  the  motor  piston  and  the  pilot  valve  operate  with  one 
pressure  of  water,  while  the  main  valve  controls  the  flow  of  water  from 
another  source,  which  is  of  much  higher  pressure.  The  location  and  rela- 
tions of  the  levers  L,  L"  and  N  can  be  more  fully  understood  from  an 
examination  of  the  plan  view  at  the  top  of  Fig.  172.  The  external 
appearance  of  these  valves  is  shown  in  the  photographic  view  Fig.  173. 
Allowance  must  be  made,  however,  for  the  fact  that  the  latter  is  the 
reversed  view,  from  the  rear  of  Fig.  172. 

In  some  machines  the  pilot  valve  is  rendered  unnecessary  by  the  use 
of  a  hand-wheel  in  the  car,  the  leverage  of  which  makes  it  possible  to 
move  the  main  valve  directly.  When  this  arrangement  is  used  with 
high-pressure  machines,  the  valve  is  altered  in  construction  in  the  manner 
clearly  shown  in  Fig.  174.  In  this  drawing  the  inlet  and  outlet  connec- 
tions are  on  the  left  instead  of  on  the  right,  as  in  Fig.  172.  This  is  due 
to  the  fact  that  the  drawing  shows  the  valve  from  the  reverse  side.  The 
only  actual  difference  between  this  valve-gear  and  the  one  shown  in 
Fig.  172  is  that  in  place  of  the  pilot  valve  and  the  motor  cylinder,  a  rack 
F  and  actuating  pinion  F'  are  used;  the  rack  being  connected  with  the 
ends  of  the  main  valve  in  the  same  manner  as  the  motor  piston-rod. 
The  arms  E  E  are  the  counterparts  of  the  arms  /  /.  In  Fig.  174  the  ports 
L  L  are  shown  as  long  slots,  but  the  common  construction  is  to  make 
them  in  the  form  of  numerous  small  holes,  so  as  to  prevent  the  water 
from  drawing  the  edges  of  the  cup  packings  into  them. 

MODIFICATIONS  IN  VALVES   MADE  TO  BE  OPERATED  BY   MAGNETS. 

The  valves  of  Fig.  172  are  also  made  so  as  to  be  operated  by  magnets 
whenever  it  is  desired  to  control  the  car  by  the  movement  of  a  small 
electric  switch  instead  of  the  lever  used  with  the  running-  and  standing- 
rope  gear.  The  advantages  of  the  electric  switch  in  the  car  are  that 
less  space  is  required  for  its  manipulation,  which  is  a  matter  of  consider- 
able importance  if  the  car  is  small,  and  that  all  the  more  or  less  com- 
plicated rope  connections  between  the  car  lever  and  the  lever  of  the 
pilot  valve  are  dispensed  with ;  in  their  place  are  substantial  small  cop- 
per wires  within  a  flexible  cable  extending  from  the  under  side  of  the  car 
to  a  point  about  half  the  way  up  the  elevator  well. 

The  modifications  made  in  the  valve  when  arranged  to  be  operated 
by  magnets  are  shown  in  Figs.  175  and  176,  the  one  being  a  sectional 
elevation  through  the  main  and  the  pilot  valves,  and  the  other  an  external 
view  taken  at  right  angles  to  the  former.  In  Fig.  175  it  will  be  noticed 
that  the  main  valve  and  the  motor  cylinder  and  piston  are  the  same  a^ 
in  Fig.  172,  but  there  is  some  modification  in  the  pilot  valve.  This  con- 
sists in  substituting  a  solid  valve  for  the  valve  with  cup  packings,  and 


OPERATION  OF  THE  MAIN  AND  PILOT  VALVES 


203 


this  change  is  made  in  order  to  reduce  the  frictional  resistance  and  make 
it  possible  to  operate  the  valve  with  magnets  of  reasonable  size.  The  solid 
pilot  valve  is  made  a  perfect  fit  by  grinding  and  with  ordinary  care  will 
remain  tight  for  a  long  time,  especially  if  the  pressure  of  the  water 
used  to  operate  the  motor  piston  is  low,  and  this  can  be  made  as  low  as 
desired  by  simply  increasing  the  diameter  of  the  motor  piston.  For  the 
purpose  of  making  the  pilot  valve  move  as  easily  as  possible  and  with 


FIG.   175 

the  same  effort  whether  lifted  or  depressed,  the  lever  L"  is  extended  to 
the  right,  as  shown,  and  carries  at  its  outer  end  a  weight  that  is  carefully 
adjusted  to  balance  the  combined  weight  of  the  pilot  valve,  the  lever  L 
and  the  connecting-rods  L'  and  M.  The  shaft  P  is  provided  with  a  coup- 
ling N  that  connects  it  mechanically  with  the  rock-shaft  of  the  magnets 
which  operate  the  valve;  but  the  connection  is  made  through  insulating 


204 


HYDRAULIC  ELEVATORS 


material,  as  is  indicated  by  the  heavy  black  lines  in  Fig.  176,  so  as  to 
prevent  any  electrical  connection  between  the  two  parts. 

The  magnets  are  of  the  same  type  as  those  described  in  connection 
with  vertical  low-pressure  elevators  and  act  in  the  same  manner.    While 


FIG.  176 

magnet  control  operated  by  a  small  electric  switch  in  the  car  is  very 
desirable  so  far  as  compactness  and  simplicity  of  apparatus  are  concerned. 
:t  has  the  objection  that  with  it  the  operator  cannot  vary  the  car  speed 
in  the  same  way  as  with  the  car  lever  and  standing-rope  rig,  and  for  that 
reason  the  lever,  although  more  cumbersome,  is  still  used  in  nearly 
all  cases. 


CHAPTER  XXXI 

CONSTRUCTION   AND   OPERATION   OF   THE  ACCUMULAT- 
ORS AND  THE  AUTOMATIC  VALVES  USED 
WITH  THEM 

For  high-pressure  elevators  accumulators  are  always  used  in  place  of 
pressure  tanks.  The  latter  are  practically  out  of  the  question  for  such 
service,  because  no  matter  how  perfect  all  the  parts  may  be,  the  air  in 
the  pressure  tank  is  sure  to  escape,  so  that  from  time  to  time  it  has  to 
be  renewed.  With  low-pressure  systems  this  is  easily  done  by  drawing  in 
air  with  the  water,  the  pumps  being  made  so  as  to  draw  in  air  whenever 
required,  that  is,  the  same  pump  can  be  used  to  pump  the  air  as  well  as 
the  water.  With  the  high-pressure  system  this  arrangement  would  not  be 
desirable,  and  to  provide  a  regular  air  pump  to  force  air  into  the  tank 
whenever  necessary  would  be  objectionable  on  account  of  the  high  pres- 
sure. To  pump  the  air  successfully  would  require  two-stage  compression 
to  the  required  pressure.  Even  after  doing  this,  the  tank  system  would 
not  be  equal  to  the  accumulator  because  with  it  the  pressure  cannot  be 
kept  constant,  whereas  with  the  accumulator  it  cannot  vary,  because  it 
does  not  depend  upon  the  amount  of  water  within  the  accumulator,  but 
upon  the  weight  of  the  accumulator  plunger. 

In  large  elevator  installations,  where  there  are  many  elevators  and  a 
number  of  pumps  to  supply  the  water,  one  accumulator  may  supply 
several  elevators,  and  these  may  be  connected  all  in  one  system,  so 
that  water  can  be  drawn  from  any  one  of  the  accumulators  to  operate 
any  one  of  the  elevators,  or  the  plant  may  be  divided  into  a  number  of 
independent  sections.  If  there  is  only  one  elevator,  there  will  be  one 
accumulator,  and  its  capacity  will  be  very  much  larger  in  proportion  to 
the- elevator  than  where  there  are  several  elevators  operating  from  one 
accumulator.  Thus  if  there  are  two  elevators,  the  accumulator  will  not 
be  much  larger  than  for  one  car,  and  for  three  cars  it  will  not  be  much 
larger  than  for  two.  The  accumulator  in  a  plant  where  the  elevators 
are  in  constant  service  is  only  of  sufficient  capacity  to  supply  water  dur- 
ing any  short  interval  when  the  pumps  are  overtaxed,  and  this  is  not 
often. 

CONSTRUCTION  OF  THE  ACCUMULATOR. 

The  construction  of  an  elevator  accumulator  made  by  the  Otis  Ele- 
vator Company  is  shown  by  Fig.  177,  a  sectional  elevation  and  a  plan  view 

205 


206 


HYDRAULIC  ELEVATORS 


being  shown.  This  is  one  of  many  designs  used,  but  is  the  most  common, 
because  it  is  so  constructed  as  to  require  the  least  amount  of  head  room, 
and  in  practically  every  installation  head  room  is  limited.  The  accumu- 
lator cylinder  is  shown  at  C.  At  the  upper  end  of  the  plunger  P  is 
mounted  a  crosshead  B  from  which  are  suspended  four  strong  rods  A. 


FIG.   177 

These  rods  pass  through  a  number  of  weights  W  and  a  lower  retaining 
flange  D.  The  number  of  weights  depends  upon  the  pressure  required, 
and  is  made  such  that  the  combined  weight  of  the  plunger,  the  crosshead, 
the  rods  A,  the  flange  D  and  the  weights  W  produces  the  required  pressure 
upon  the  end  of  the  plunger.  The  weights  have  an  opening  through  the 


CONSTRUCTION  AND  OPERATION  OF  THE  ACCUMULATORS 


207 


center  that  is  large  enough  to  pass  the  weights  over  the  cylinder  and  any 
projecting  parts  connected  with  it.  In  this  way  the  hight  is  much  less 
than  it  would  be  if  the  weights  were  placed  directly  on  top  of  the  plunger. 
When  nearly  all  the  water  is  drawn  out  of  the  accumulator,  the  plunger 


innrvrl . 


FIG.  178 


FIG.   179 


descends  to  the  position  shown  in  the  drawing  and  the  lower  part  of  the 
flange  D  strikes  upon  the  buffer  block  of  hard  wood  in  the  top  of  the 
base  casting  F.  When  the  plunger  is  raised  to  its  highest  position  it 
is  prevented  from  being  forced  entirely  out  of  the  cylinder  by  the  enlarged 
head,  which  is  securely  held  in  position  by  bolts.  This  head  brings  up 


2o8  HYDRAULIC  ELEVATORS 

against  a  shoulder  at  the  top  of  the  cylinder  and  prevents  the  plunger  from 
rising  any  farther.  The  plunger  is  held  in  line  with  the  cylinder  by  means 
of  the  guides  E,  as  shown  in  the  plan  view.  It  is  not  desirable  to  allow 
the  plunger  to  come  down  and  strike  the  lower  buffer,  or  to  run  up  until 
it  hits  the  upper  stop ;  hence,  means  are  provided  to  stop  the  plunger  auto- 
matically before  it  runs  either  too  far  up  or  too  far  down.  This  is 
accomplished  by  stopping  the  pump  when  the  plunger  has  reached  the 
upper  limit,  and  if  there  are  several  pumps  and  accumulators,  by  in  addi- 
tion closirig  the  entrance  so  that  no  more  water  can  be  pumped  in, 
although  the  water  in  the  accumulator  will  be  free  to  run  out.  If  the 
water  is  drawn  out  so  as  to  make  the  plunger  descend  to  the  lower  safe 
limit,  the  opening  into  the  accumulator  is  closed  so  that  no  more  water 
can  run  out,  but  the  closing  does  not  prevent  more  water  from  passing 
into  the  cylinder. 

The  way  in  which  all  this  is  accomplished  is  shown  in  Figs.  178  and 
179.  These  drawings  show  two  elevations  of  an  accumulator,  at  right 
angles  to  each  other,  equipped  with  an  automatic  stop-valve,  and  addi- 
tional means  for  stopping  the  pump.  The  accumulator  is  shown  at  about 
the  mid  position.  Should  it  rise,  a  plate  secured  to  the  lower  weight  sup- 
porting the  flange  D  directly  under  the  weight  K  will  lift  the  latter.  The 
rope  L  runs  to  the  starting  lever  of  the  pump  and  when  the  weight  K 
is  hanging  in  the  air,  it  holds  up  the  lever  and  thereby  keeps  the  pump 
running,  but  as  soon  as  it  is  lifted  by  the  plate  on  the  accumulator,  a 
counterweight  or  spring  pulls  the  lever  in  the  opposite  direction  so  as  to 
stop  the  pump.  The  automatic  stop  valve  is  located  at  G  and  is  moved  by 
the  sprocket  chain  H,  upon  which  are  mounted  stop  balls  /  and  /'.  When 
the  accumulator  is  full  the  stop  /  is  struck  by  the  arm  I,  attached  to  the 
weights  W ' ,  and  the  valve  G  is  rotated  so  as  to  prevent  more  water  being 
forced  into  the  cylinder.  When  the  water  is  drawn  out  enough  to  cause 
the  arm  /  to  strike  the  lower  stop  /',  the  stop  valve  G  is  moved  in  the 
opposite  direction  until  it  is  closed,  preventing  further  escape  of  water 
from  the  cylinder. 

When  the  accumulator  is  in  any  intermediate  position,  the  weights  M 
and  M'  act  to  move  the  valve  G  into  the  central  position,  in  which  water, 
can  pass  through  it  freely  in  either  direction.  These  weights  draw  the 
valve  into  the  central  position  because  they  are  hung  on  a  chain  that 
passes  over  the  sprocket  V  which  is  fixed  on  the  same  shaft  as  the 
sprocket  U ,  over  which  the  valve-moving  chain  H  passes.  The  weights 
run  on  guides,  as  shown  in  Fig.  179,  and  when  one  of  them  is  raised 
by  the  rotation  of  the  sprocket  U  the  other  one  does  not  go  down,  because 
it  is  held  by  the  nuts  on  the  lower  end  of  the  guide  rods ;  hence,  the  lifted 
weight  hangs  on  the  wheel  V  and  acts  to  rotate  it  back  to  the  central  posi- 


CONSTRUCTION  AND  OPERATION  OF  THE  ACCUMULATORS         209 


tion  as  soon  as  the  weights  W  have  moved  far  enough  away  to  permit  it 
to  descend  to  the  normal  position. 

CONSTRUCTION    AND    OPERATION    OF    THE    AUTOMATIC    STOP   VALVE   IN    THE 
OTIS  VERTICAL  MACHINE. 

The  construction  and  operation  of  the  stop  valve  B  can  be  understood 
from  Fig.  180,  which  shows  vertical  central  sections  at  right  angles  to 
each  other.  In  the  cut  it  will  be  seen  that  there  are  two  spring-retained 
check-valves  T,  T',  set  so  as  to  open  in  opposite  directions.  If  the  main 
valve  R  is  in  the  central  position,  water  can  flow  through  from  the  pipe 
coming  from  the  pumps  into  the  accumulator,  following  the  path*  of  the 


FIG.   180 

arrows  a.  If  the  elevator  cylinders  draw  more  water  than  the  pumps  can 
supply,  the  deficiency  will  pass  out  of  the  accumulator  along  the  path  of 
the  arrows  b.  If  the  accumulator  is  filled,  the  rotation  of  the  sprocket 
wheel  O  on  the  shaft  P  will  turn  the  pinion  P'  and  through  the  inter- 
mediate wheel  P"  will  rotate  the  segment  Q  and  thereby  turn  the  main 
valve  R  so  as  to  close  the  inlet  along  the  path  of  the  arrows  a.  If  the 
water  in  the  accumulator  runs  to  the  lower  limit,  the  sprocket  O  will  be 
rotated  in  the  opposite  direction  so  as  to  close  the  outlet  path  of  the 
arrows  b.  When  the  inlet  is  closed,  the  path  of  the  arrows  b  remains 
open  so  that  water  may  run  out  of  the  accumulator,  and  when  the  out- 
let path  is  closed,  the  inlet  remains  open  so  that  water  may  flow  in  and 
fill  the  accumulator.  To  understand  clearly  this  action  it  must  be  under- 
stood that  the  partition  Sf  separates  the  ports  in  which  the  check-valves 
T,  T  are  located  and  that  the  openings  in  the  valve  R  are  so  located  that 
when  the  valve  is  in  the  central  position  both  ports  are  open,  but  when  it 


2IO 


HYDRAULIC  ELEVATORS 


is  turned  in  one  direction  it  closes  the  port  of  the  valve   T,  and  when 
turned  in  the  opposite  direction  it  closes  the  port  of  the  valve  T'. 

ELECTROMAGNETIC  DEVICE    USED   FOR    CONTROLLING    THE    PUMP. 

The  arrangement  shown  in  Figs.  178  and  179  for  stopping  the  pump 
when  the  accumulator  is  full  and  starting  it  when  the  water  is  nearly  all 
drawn  out  is  purely  mechanical,  and  works  perfectly  in  practice  except 
in  cases  where  the  accumulator  and  pump  are  not  very  close  to  each 


Leather  Cup 
Pilot  Valve  Body 


FIG.  181 

other,  or  where  the  construction  of  the  building  makes  it  impracticable  to 
obtain  a  direct  rope  connection  between  the  pump  and  the  weight  K  on 
the  accumulator.  In  such  cases  an  electromagnetic  device  can  be  used 
that  will  simplify  the  construction  and  also  render  its  operation  more 
certain.  One  of  these  is  shown  in  Fig.  181,  which  gives  a  sectional  ele- 
vation of  the  device  and  a  diagram  of  its  connection  with  the  pump-start- 
ing valve.  This  type  of  apparatus  is  generally  actuated  by  placing  near 
the  travel  limits  of  the  accumulator  weights  a  pair  of  switch  contacts  that 
are  controlled  by  an  arm  projecting  from  the  weights,  in  precisely  the 
same  way  that  the  arm  /  in  Fig.  178  actuates  the  valve  G. 


CONSTRUCTION  AND  OPERATION  OF  THE  ACCUMULATORS        211 

Looking  at  both  the  illustrations  it  will  be  seen  that  when  the  differ- 
ential plunger  A  moves,  it  either  opens  or  closes  the  valve  G  and  thereby 
either  stops  or  starts  the  pump.  Suppose  that  when  the  accumulator  is  in 
the  highest  position  the  lever  H  is  over  in  the  extreme  right-hand  position, 
then  the  plunger  A  will  be  in  the  position  shown  and  the  valve  B  will  be 
drawn  up  so  as  to  connect  the  right-hand  end  of  the  cylinder  to  discharge 
its  water  through  the  lower  ports  into  the  discharge  pipe.  For  the  valve 
B  to  be  raised  into  this  position,  the  magnet  M  must  be  energized  so  as  to 
be  able  to  compress  the  spring  S ;  hence,  the  arm  on  the  accumulator  must 
close  the  switch  contacts  when  the  weights  reach  the  upper  position.  This 
movement  of  the  lever  H  will  close  the  valve  G  and  stop  the  pump,  so 
that  if  water  is  drawn  from  the  accumulator  the  plunger  will  descend,  but 
the  stationary  switch  contacts  that  were  moved  by  the  arm  on  the  weights 
will  remain  closed,  and  the  magnet  M  will  continue  energized.  When  the 
accumulator  weight  descends  low  enough  to  require  the  pump  to  be  put 
into  action,  the  stationary  switch  will  be  moved  so  as  to  open  the  circuit 
through  the  magnet  M  and  then  the  spring  S  will  push  the  valve  B  down 
so  that  water  from  the  supply  pipe  will  pass  to  the  right-hand  end  of 
cylinder  C  and  force  the  plunger  A  to  the  left,  thereby  moving  the  lever  H 
of  the  valve  G  to  the  open  position  to  start  the  pump,  which  will  continue 
running  until  the  accumulator  is  filled  again  to  the  upper  Imit,  when  the 
former  operation  will  be  repeated,  and  the  pump  will  be  stopped. 

The  switch  on  top  of  the  magnet  in  Fig.  181  is  a  type  that  is  com- 
monly used  in  connection  with  magnets  that  are  intended  to  remain  in 
service  for  a  considerable  length  of  time.  When  the  magnet  M  draws 
up  the  plunger,  the  upper  end  lifts  the  switch  lever  E,  thereby  opening  the 
contacts  F,  Fr  and  putting  a  high  resistance  into  the  circuit  of  the  mag- 
net winding;  this  reduces  the  current  to  probably  10  or  15  per  cent,  of  its 
initial  strength,  so  that  it  can  flow  through  the  coil  for  a  long  time  with- 
out heating  it  to  a  dangerous  degree. 


CHAPTER  XXXII 

AUTOMATIC  STOP  VALVES  USED  WITH  OTIS  HIGH- 
PRESSURE  MACHINES 

The  construction  and  operation  of, the  automatic  stop  valve  for  the 
elevator  machine  shown  in  Fig.  164  can  be  understood  from  an  exami- 
nation of  Fig.  182,  which  is  a  sectional  elevation.  This  valve  is  actuated 
by  the  lever  A,  and  there  are  two  of  these  levers,  one  on  the  valve  proper, 
and  the  other  at  a  point  near  the  cylinder.  The  lower  one  is  moved  when 
the  traveling  sheaves  reach  the  lowest  position,  and  the  upper  one  when 
they  reach  the  highest  position.  The  rod  L  extends  to  the  upper  limit  of 
the  sheave  travel  and  there  connects  with  a  lever  C  that  is  mounted  on  a 
stud  similar  to  B  and  connects  with  a  lever  like  the  lever  A  in  the  same 
way  that  these  parts  are  connected  in  the  drawing.  The  only  difference 
is  that  the  lower  A  lever  stands  normally  about  in  the  position  of  arrow 
M  while  the  upper  A  lever  stands  normally  in  the  position  of  arrow  N. 
The  lower  lever  is  pushed  to  the  position  in  which  it  is  here  shown  by 
a  projection  on  the  traveling-sheave  frame,  and  the  upper  lever  is  simi- 
larly pushed  into  the  position  of  arrow  O. 

If  the  car  is  going  up  the  traveling  sheave  will  be  coming  down,  and 
water  will  be  running  into  the  lifting  cylinder  through  the  valve  from  the 
lower  supply  pipe  up  into  the  machine  pipe.  Through  the  valve  the 
path  will  be  by  way  of  the  port  H  through  the  spring-supported  check- 
valve  V  into  the  port  /.  When  the  traveling  sheave  descends  low  enough 
to  move  the  lever  A  to  the  position  in  which  it  is  shown  the  valve  E 
will  be  moved  down  opposite  the  port  H  and  then  the  flow  of  water 
into  the  cylinder  will  be  stopped,  as  the  only  other  path  is  closed  by  the 
check-valve  K.  If  now  the  operator  sets  the  car  lever  so  as  to  run  down, 
the  water  in  the  cylinder  will  flow  out  and  down  the  machine  pipe  into 
the  port  /  and  thence  into  the  port  /  and  through  the  valve  K  to  the  lower 
pipe.  When  the  traveling-sheave  frame  reaches  the  upper  limit  of  travel, 
the  upper  A  lever  will  be  moved  into  the  position  of  arrow  O,  and  the 
rod  L  will  pull  up  the  valve  E  so  as  to  close  the  port  /  and  then  no  more 
water  will  be  able  to  flow  out  of  the  cylinder  and  the  car  will  be  stopped. 
When  the  car  and  traveling  sheaves  are  in  any  intermediate  position, 
the  valve  E  is  moved  to  the  central  space,  E'  by  the  action  of  the  spring 


AUTOMATIC  STOP  VALVES 


213 


S,  which  forces  the  upper  head  F  up  against  the  end  G  of  the  spring  box, 
or  the  lower  head  F'  against  the  lower  end  Gr. 

THE  AUTOMATIC  STOP  VALVE  OF  THE  OTIS  HORIZONTAL  MACHINE. 

The   automatic  stop  valve   shown  on   the   horizontal   machine,   Fig. 
165,  is  very  different  from  that  above  described.     Its  construction  is 


FIG.   182 


clearly  shown  in  Fig.  183.  The  actuating  sprocket  chain  passes  around 
the  sprocket  wheel  G  which  carries  a  beveled  pinion  G'  meshing  with  a 
segment  H,  mounted  on  the  valve  shaft  H'.  The  body  of  the  valve  F 


214 


HYDRAULIC  ELEVATORS 


carries  a  loose  segment  F'  that  fits  against  the  valve  chamber  when  forced 
outward,  but  can  be  moved  away  from  the  seat  some  distance  when  the* 
force  acts  toward  the  center  of  the  shaft.  When  the  water  flows  in  the 
direction  indicated  by  D  and  E,  the  valve  is  turned  counter-clockwise  to 
stop  the  flow  and,  consequently,  the  elevator  car.  But  when  the  car 
lever  is  reversed  to  run  in  the  opposite  direction,  the  flow  of  water  through 
the  valve  will  be  reversed  and  the  segment  F'  will  be  pushed  away  from 


Plan  'View 

•with  Gear  Cover 

removed. 


Section  at 
Center  Line  A-A 


FIG.   183 


the  valve  seat  so  that  a  sufficient  amount  of  water  may  pass  through  to 
enable  the  car  to  start  up  at  a  moderate  speed.  The  operation  of  this  valve 
will  be  recognized  as  identical  with  that  of  the  automatic  stop  valve  used 
in  the  low-pressure  vertical  elevators  described  in  former  chapters.  When 
the  car  moves  away  from  the  landing,  the  valve  F,  F'  is  returned  to  tha 
central  position,  in  which  it  is  drawn  by  the  action  of  a  centering  weight 
or  spring.  No  device  of  this  kind  is  shown  in  the  drawings,  but  the  valve 
is  not  used  without  it.  The  general  appearance  of  this  valve  can  be  seen 
in  the  photographic  views,  Figs.  184,  185,  186. 

Another  design  of  automatic  stop-valve  used  generally  with  vertical- 
cylinder  high-pressure  machines  is  shown  in  Fig.  187.  The  way  in  which 
it  is  actuated  is  clearly  shown  in  Fig.  188.  The  operating  chain  passes 
around  the  sprocket  G  which  is  mounted  on  one  end  of  the  shaft  /,  Fig. 
187.  On  the  other  end  of  this  shaft  there  is  a  pinion  that  meshes  into  a 


AUTOMATIC  STOP  VALVES 


215 


gear  /  mounted  on  the  valve  shaft.  The  valve  is  constructed  in  the  same 
manner  as  that  of  Fig.  183  and  operates  in  the  same  way.  On  the  shaft 
/  is  mounted  a  large  wheel  L  and  to  this  is  fastened  a  chain  that  carries 


v 


FIG.  184  FIG.  185  FIG.  186 

the  centering  weight,  as  shown  in  Fig.  188.  This  chain  is  held  in  the  cen- 
tral position  by  the  guide  wheels  L'  L'.  It  will  be  noted  that  this  part 
of  the  construction  is  the  same  as  that  of  the  stop-motion  valve  of  the 


Longitudinal  Section  of  Valve 
in  Central  Position 


Cross  Section  of  Valv* 
in  Central  Position  -  Wick  Open 


FIG.  187 

Whittier  horizontal  pulling  machine.  The  operating  rope  carries  stop- 
balls  that  are  struck  by  the  arm  projecting  from  the  traveling-sheave 
frame.  This  rope  runs  the  entire  length  of  the  guides  in  which  the  sheave 


2l6 


.HYDRAULIC  ELEVATORS 


frame  travels.  At  the  lower  end  a  sprocket  chain  is  connected  with  the 
ends  of  the  rope  and  passes  around  sprocket  wheel  G  so  as  to  move  the 
valve  in  exact  time  with  the  movement  of  the  sheave  frame. 

OTHER  DEVICES   USED    WITH    HIGH-PRESSURE    SYSTEMS. 

The  air  chamber  shown  at  Q,  in  Fig.  164,  is  constructed  in  the  way. 
shown  in  Fig.  189.    The  object  of  this  air  chamber  is  to  smooth  out  any 


C.oUtln, 


FIG.  188  FIG.  189 

slight  pulsations  in  the  water  that  may  not  be  taken  out  by  the  air  cham- 
bers attached  to  the  pump.  In  the  low-pressure  systems  such  a  device  is 
not  required  because  the  pumps  deliver  into  a  pressure  tank  and  the  water 
flows  from  this  into  the  elevator  cylinders  in  an  even  stream.  In  high- 
pressure  systems  this  is  not  the  case;  the  pumps  are  continually  forcing1 


AUTOMATIC  STOP  VALVES  217 

water  into  the  system  and  the  lifting  cylinders  are  drawing  it  out,  and 
unless  some  device  is  provided  that  can  act  like  a  cushion  every  pulsation 
of  the  pumps  that  is  not  subdued  by  the  pump  air  chamber  is  sure  to  be 
transmitted  to  the  elevator  cylinders  and  thence  to  the  elevator  cars. 

The  difference  between  the  air  chamber  in  Fig.  189  and  those  com- 
monly used  for  similar  purposes  is  that  it  is  provided  with  a  check-valve 
to  prevent  the  air  from  getting  into  the  pipes.  If  the  lower  end  of  the 
chamber  were  not  closed  by  the  valve  D  the  air  could  expand  enough  to 
force  all  the  water  and  a  part  of  the  air  out  of  the  chamber  and  into  the 
pipe  line  connecting  with  A,  B,  if  for  any  reason  there  should  be  a 
momentary  drop  in  pressure  of,  say,  25  or  30  per  cent. ;  and  although  this 
is  not  very  likely  to  occur,  it  can  happen,  and  would  cause  trouble,  as  the 
air  would  eventually  get  into  the  lifting  cylinders  and  cause  the  car  to 
bounce  when  stopped  at  the  floors.  The  valve  D  is  carried  on  the  lower 
end  of  a  float  C  so  that  when  the  water  rises  in  the  chamber  above  a  cer- 
tain point  the  valve  will  float  off  its  seat,  but  if  the  pressure  in  the  pipe 
line  drops  below  this  point  the  float  will  not  sustain  the  valve,  so  it  will 
settle  down  on  its  seat  and  thus  prevent  the  water  and  air  from  being 
forced  out  into  the  pipe  line.  The  level  of  the  water  in  the  chamber  is 
adjusted  by  so  setting  the  nuts  on  the  rods  that  hold  the  adjusting  springs 
that  more  or  less  of  the  weight  is  supported.  If  the  nuts  are  run  down 
more  weight  will  have  to  be  lifted  by  the  float  and  as  a  result  the  water 
level  will  be  raised ;  in  like  manner  running  the  nuts  up  on  the  rods  will 
lower  the  water  level. 

THE    SPEED    CONTROLLER. 

The  speed  controller  shown  at  R  in  Fig.  187  is  constructed  as  indicated 
in  Fig.  190,  which  shows  a  side  elevation  and  a  section  at  right  angles  to 
this  elevation.  The  external  appearance  is  shown  in  the  photographic 
view,  Fig.  191.  Looking  at  Fig.  190,  it  will  be  seen  that  the  spring  K 
acts  through  the  levers  G,  G  to  press  against  the  ends  of  the  valve-stem  A. 
These  levers  G,  G  are  pivoted  on  the  heads  of  the  valve  casing  so  that 
their  tendency  is  to  keep  the  valve  B  in  the  central  position.  The  gover- 
nor is  connected  in  the  pipe  between  the  main  valve  and  the  lifting  cyl- 
inder, and  the  water  in  entering  or  passing  out  of  the  cylinder  flows 
through  its  valve  chamber,  from  the  side  C  to  the  side  D  or  in  the  reverse 
direction.  The  water  flowing  through  must  pass  through  the  openings 
E,  E  in  the  valve  B  before  it  can  reach  the  outlet,  no  matter  in  which 
direction  it  passes  through.  When  water  passes  through  contracted  open- 
ings it  suffers  a  considerable  loss  of  pressure  so  that  if  it  has  a  pressure 
of,  say,  100  pounds  when  it  reaches  the  lower  side  of  the  valve  B,  coming 
in  through  the  port  C,  it  may  not  have  more  than  95  pounds  pressure 
after  passing  through  the  openings  E,  E. 


2l8 


HYDRAULIC  ELEVATORS 


As  the  pressure  on  the  forward  side  of  the  valve  B  is  five  pounds  more 
than  on  the  leaving  side,  there  will  be  this  pressure  available  to  move  the 
valve  away  from  the  central  position  against  the  tension  of  the  spring  K. 
This  pressure  will  remain  constant  even  if  the  pressure  of  the  water  that 
passes  through  the  valve  varies  widely,  because  the  loss  of  pressure  sus- 
tained by  the  water  in  passing  through  the  contracted  openings  E,  E 


FIG.  190  FIG.   191 

depends  entirely  upon  the  velocity  of  flow  and  is  not  changed  by  varia- 
tions in  the  pressure  of  the  water.  This  being  the  case,  the  extent  to  which 
the  valve  B  is  carried  beyond  the  central  position  by  the  difference  in  the 
water  pressures  on  its  two  sides  will  depend  upon  the  velocity  of  the  stream 
flowing  through  the  openings  E,  E,  or  upon  the  quantity  of  water  thai 
passes  through  in  a  unit  of  time. 

The  water  that  passes  through  the  openings  E,  E  gets  into  and  passes 
out  of  the  valve  cylinder  through  a  large  number  of  holes  that  are  drilled 
on  spiral  lines,  and  are  in  such  a  position  that  when  the  valve  B  moves 
slightly  away  from  the  central  position  it  begins  to  cover  these  holes,  and 
the  farther  it  moves,  the  more  holes  it  covers.  Consequently,  its  move- 
ment away  from  the  central  position  closes  more  and  more  of  the  open- 
ings through  which  the  water  passes  out  of  the  valve  cylinder,  and  thereby 
reduces  the  quantity  of  water  that  flows  through;  and  as  the  car  speed 


AUTOMATIC  STOP  VALVES 


219 


depends  upon  the  rapidity  with  which  the  water  passes  in  or  out  of  the, 
lifting  cylinder,  the  velocity  cannot  vary  much  from  the  standard  for  which 
the  governor  is  adjusted. 

If  the  car  is  lightly  loaded  and  starts  to  run  fast,  the  increased  velocity 
of  the  water  through  the  openings  E,  E  will  develop  a  greater  difference 
in  pressure  between  the  two  sides  of  the  valve,  and  as  a  consequence  the 
valve  B  will  be  carried  farther  away  from  the  central  position  and  will 
close  up  more  outlet  holes  in  the  cylinder,  reducing  the  quantity  of  water 


FIG.  192 

passing  through  it  and  thereby  preventing  the  car  speed  from  increasing. 
This  controller  cannot  maintain  a  perfectly  constant  speed,  because  it  can- 
not act  unless  the  velocity  of  the  water  changes  to  some  extent  just  as 
an  engine  governor  cannot  act  unless  the  speed  changes  slightly,  but  it 
can  be  proportioned  so  as  to  keep  the  speed  very  nearly  constant.  In 
practice  the  maximum  speed  variation  is  not  usually  more  than  5  per  cent. 
As  is  well  known,  if  when  water  is  flowing  through  a  long  pipe  at  a 
high  velocity  its  motion  is  suddenly  stopped,  the  tendency  of  the  stream  is 
to  keep  on  moving,  and  if  there  is  no  space  into  which  it  can  move,  a 
violent  water-ram  effect  is  produced.  In  high-pressure  elevator  systems 
this  water-ram  effect  is  much  greater  than  in  low-pressure  systems, 


22O  HYDRAULIC  ELEVATORS 

owing  to  the  fact  that  the  water  flows  through  the  pipes  at  a  higher  veloc- 
ity. The  loss  of  pressure  by  the  flow  of  water  through  the  pipes  depends 
upon  the  velocity,  and  as  in  low-pressure  systems  the  pipe  loss  must  be 
kept  much  lower  than  in  high-pressure  systems,  the  velocity  of  flow 
through  the  pipes  must  be  much  lower.  Suppose  the  system  operates  with 
a  pressure  of  100  pounds,  and  that  the  water  flowing  through  the  pipes 
at  a  certain  velocity  loses  10  pounds  pressure  by  the  time  it  reaches  the 
cylinder ;  then  if  there  is  another  system  operating  with  a  pressure  of  750 
pounds,  a  loss  of  75  pounds  in  pipe  friction  can  be  allowed  without  giving 
any  lower  efficiency.  In  practice  this  is  not  done;  the  efficiency  of  the 
high-pressure  systems  is  made  greater,  but  the  actual  amount  of  loss  in 
the  pipes  is  several  times  as  great,  this  increase  being  due  principally  to 
increasing  the  velocity  of  the  water  through  the  pipes.  It  is  on  this 
account  that  while  in  low-pressure  systems  the  water  hammer  effect  is 
not  serious,  in  high-pressure  systems  it  is  sufficient  to  require  the  use  of 
devices  to  subdue  it  if  the  pipes  are  unusually  long.  Such  a  device  is 
shown  in  Fig.  192  and  is  simply  what  may  be  called  a  mechanical  air 
chamber.  If  an  ordinary  air  chamber  were  placed  at  the  end  of  a  long 
pipe  line  if  would  eliminate  the  water-ram  effect,  as  the  water  would 
rush  into  it  and  compress  the  air,  but  if  the  air  worked  out,  as  it  most 
likely  would  in  a  short  time,  the  chamber  would  be  useless  until  filled 
with  air  again.  To  arrange  such  an  air  chamber  so  as  to  replenish  the  air 
whenever  necessary  would  involve  considerable  additional  piping,  which 
in  addition  to  the  expense  would  be  objectionable  as  it  would  afford 
another  way  in  whiah  air  could  get  into  the  lifting  cylinder.  When  the 
device  shown  in  Fig.  192  is  connected  to  the  end  of  a  long  pipe,  the  stream 
of  water  rushing  into  it  when  the  flow  through  the  regular  channel  is  sud- 
denly closed  causes  the  plunger  E  to  move  up  out  of  the  cylinder  and  com- 
press the  springs  D,  and  the  stronger  ones  above  them  if  necessary. 
Thus  the  force  of  the  water  ram  is  expended  in  compressing  springs 
instead  of  air,  and  when  the  velocity  of  the  water  is  exhausted  the  springs 
force  the  plunger  E  back  into  the  cylinder,  ready  to  receive  the  next  blow 
struck  by  the  water. 


CHAPTER  XXXIII 

ADJUSTMENT  AND  CARE  OF  AUTOMATIC  STOP  VALVES 
AND  MECHANISM  OF  HIGH-PRESSURE  ELEVA- 
TORS; HOW)  TO  PACK  THE  DIFFERENT 
PARTS;  KINDS  OF  PACKING  USED 

The  automatic  stop  valves  of  high-pressure  elevators  and  their  actu- 
ating mechanism  require  the  same  attention  as  those  of  low-pressure 
machines,  and  keeping  them  in  perfect  adjustment  and  running  order  at  all 
times  is  just  as  necessary,  because  the  safety  of  the  elevator  depends  on 
them  in  the  same  degree.  Several  designs  of  automatic  stop  valve  are 
shown  in  the  description  of  high-pressure  machines  and  there  are  several 
others  that  were  not  shown.  All  those  described,  with  the  exception  of 
Fig.  182,  are  substantially  the  same  as  those  shown  in  connection  with 
low-pressure  machines.  Stop  valves  of  this  kind,  in  almost  every  case,  are 
operated  by  means  of  an  actuating  rope  upon  which  stop  balls  are  secured 
at  the  proper  points  to  bring  the  car  to  a  state  of  rest  level  with  the  top 
and  bottom  floors ;  and  what  has  been  said  in  previous  chapters  relative  to 
the  care  and  adjustment  of  such  mechanism  applies  equally  to  the  stop 
valves  and  actuating  devices  used  in  high-pressure  systems. 

The  valve  in  Fig.  182,  however,  requires  some  additional  consideration 
owing  to  the  fact  that  it  can  be  got  so  far  out  of  adjustment  as  to  cause 
considerable  damage.  The  illustration  shows  that  the  connecting-rods  that 
connect  the  crank  lever  C  with  the  valve  stem  and  with  the  rod  L  that 
runs  up  to  the  top  stop  lever  are  provided  with  right-  and  left-hand  screw 
couplings  by  means  of  which  their  length  can  be  varied.  It  also  shows 
that  the  valve  E  is  held  normally  in  the  central  position  by  the  spring  5", 
which  forces  the  upper  head  F  against  the  upper  end  of  the  spring  cas- 
ing, and  the  lower  head  F'  against  the  lower  end  G'.  This  being  the  case, 
any  change  made  in  the  length  of  the  connections,  whether  with  the  valve 
or  with  the  rod  L,  will  have  the  effect  of  varying  the  position  of  the  lever 
C  and  likewise  that  of  the  corresponding  lever  at  the  upper  end  of  the 
rod  L.  All  this  will  appear  perfectly  clear  by  the  aid  of  the  diagram, 
Fig.  I93»  where  E'  represents  the  position  in  which  the  valve  E  is  nor- 
mally held,  while  line  A  represents  the  normal  position  of  lever  A  and  a, 
the  position  into  which  it  is  pushed  by  the  lower  roller  R  mounted  on  the 
traveling-sheave  frame  T,  b  represents  the  normal  position  of  the  upper 
A  lever  and  B  and  B'  are  the  centers  around  which  these  levers  move. 


221 


2) 


R' 


FIG.  194 


FIG.  195 


ADJUSTMENT  AND  CARE  OF  AUTOMATIC  STOP  VALVES  223 

The  turnbuckles  by  means  of  which  the  connections  with  the  upper  end  of 
the  valve  and  the  lower  end  of  the  rod  L  are  varied  in  length  are  repre- 
sented by  D  and  F.  With  D  adjusted  so  that  the  lever  C  stands  in  the 
horizontal  position  when  the  valve  is  in  the  central  position  E' ,  if  L  is  of 
the  same  length  as  the  distance  between  B  and  B',  the  upper  lever  C  will 
also  rest  in  the  horizontal  position,  the  lower  lever  A  will  be  in  the  posi- 
tion shown,  and  the  upper  lever  A  in  the  position  of  the  line  b.  If  now  the 
traveling  sheave  comes  down,  the  stop  roller  R  will  strike  A  and  depress  it 
to  the  position  a  to  shift  the  stop  valve  to  the  stop  position.  If  the  traveling 
sheave  runs  upward,  the  upper  stop  roller  R  will  strike  the  lever  A  in  the 
position  b  and  carry  it  to  the  position  b'  to  move  the  valve  to  the  upper 
stop  position.  Now  suppose  the  turnbuckle  D  is  lengthened ;  then  since  the 
valve  E  will  be  held  in  the  positron  E'  by  the  tension-  of  the  spring  5"  ( see 
Fig.  182),  the  lever  C  will  be  moved  upward,  and  if  rod  L  is  not  short- 
ened, the  upper  lever  C  will  be  forced  up  above  the  horizontal  position, 
and  so  will  the  lever  A'.  If,  with  this  change  in  the  adjustment,  the  trav- 
eling sheave  runs  down  the  stop  roller  R  will  strike  the  lever  A  when  it 
reaches  the  position  /,  because  the  lever  A  will  now  rest  in  the  position  of 
broken  line  a'  and  when  the  roller  has  reached  the  position  /  the  valve  will 
be  moved  to  the  stop  position,  thus  stopping  the  movement  of  the  travel- 
ing sheave  within  the  distance  x;  while  before  the  turnbuckle  D  was 
lengthened  the  roller  R  traveled  from  R'  to  R"  to  move  the  valve  to  the 
stop  position,  equal  to  the  distance  y. 

Looking  at  the  upper  end  of  the  diagram  it  is  clear  that,  as  the  lever 
A'  has  been  shifted  to  the  position  in  which  it  is  drawn,  the  upper  stop 
roller  R  on  the  traveling  sheave  will  have  to  reach  the  position  b'  before  it 
begins  to  move  the  lever  A' ,  and  as  the  lever  will  have  to  move  to  the 
position  A!  to  close  the  valve,  the  latter  will  not  be  closed,  and  as  a  result 
the  traveling  sheave  will  continue  moving  until  stopped  by  some  other 
means.  From  all  this  it  can  be  seen  that  unless  the  turnbuckle  D  is 
lengthened  very  little,  the  upper  lever  A  will  be  rotated  so  far  around 
that  the  stop  roller  on  the  traveling  sheave  will  not  be  able  to  move  it 
far  enough  to  close  the  stop  valve  E.  If,  however,  the  connection  F 
is  reduced  in  length  so  as  to  cause  the  lever  C'  to  rest  in  the  horizontal 
position  normally,  then  the  traveling-sheave  stop  roller  R  will  be  able  to 
close  the  valve  fully  because  the  lever  A'  will  have  to  be  moved  from  the 
position  b  to  the  position  b'. 

By  adjusting  the  lengths  of  the  connections  D  and  F,  the  distance  the 
car  will  travel  after  the  stop  valve  begins  to  move  can  be  varied.  Suppose 
D  is  made  longer,  then  the  lever  C  will  be  pushed  upward,  as  shown  in 
Fig.  194,  and  if  F  is  shortened  twice  as  much  as  D  is  lengthened,  the 
upper  lever  C'  wil  rest  below  the  horizontal  line,  so  that  the  upper  and 


224  HYDRAULIC  ELEVATORS 

the  lower  levers  A  will  stand  at  the  same  angles  above  and  below  the 
horizontal;  consequently  the  distance  the  traveling  sheave  will  move  at 
each  end  of  its  travel  before  the  car  stops  will  be  the  same,  being  equal 
to  the  distance  between  the  circles  R'  and  R" ' ,  which  is  less  than  the  dis- 
tance y  in  Fig.  193,  because  D  has  been  made  longer.  Suppose  now  that  D 
is  made  shorter ;  then  the  lever  C  will  be  drawn  as  shown  in  Fig.  195,  and 
to  cause  the  upper  lever  A  to  rest  at  the  same  angle  above  the  horizontal 
line  that  the  lower  lever  A  does  below  this  line,  F  will  have  to  be  length- 
ened out  just  twice  as  much  as  D  was  shortened.  With  this  change  in 
the  adjustment,  the  traveling  sheave  will  have  to  move  the  distance  indi- 
cated by  circles  R  and  R'  to  shift  the  valve  E  to  the  stop  position,  and  this 
distance  is  more  than  y  in  Fig.  193. 

It  will  be  noticed,  however,  that  in  Fig.  194  the  valve  will  be  closed 
sooner  than  in  Fig.  195,  this  being  clearly  indicated  by  the  position  of  the 
circle  R"  at  the  lower  end  of  both  diagrams.  This  simply  means  that  if 
the  change  indicated  in  Fig.  194  is  made  the  car  will  stop  short  of  the 
floor  at  the  top  and  bottom,  and  if  the  change  indicated  in  Fig.  195  is 
made  the  car  will  run  beyond  the  floor  at  both  landings.  From  this  it 
follows  that  if  the  car  runs  too  far  at  one  or  both  landings,  it  can  be  made 
to  stop  even  with  the  floor  by  making  D  longer,  being  careful  to  shorten  F 
the  proper  amount ;  and  if  it  stops  short  of  the  proper  point  the  defect  can 
be  remedied  by  making  D  shorter  and  F  longer.  If  it  is  desired  to  effect 
the  stop  in  a  shorter  distance,  and  still  have  the  car  stop  even  with  the 
floor,  the  only  way  to  do  it  will  be  by  shifting  the  whole  valve  so  that  the 
distance  between  centers  and  B  and  B'  may  be  increased  in  the  proper 
amount.  If  it  is  desired  to  make  the  stop  slower,  the  valve  will  have 
to  be  shifted  so  as  to  reduce  the  distance  between  B  and  B'. 

DANGEROUS    TO   CHANGE   ADJUSTMENTS. 

It  should  be  remembered,  however,  that  unless  one  is  thoroughly 
familiar  with  the  operation  of  every  part  of  an  elevator  system  it  is  very 
dangerous  to  make  changes  in  the  adjustment,  unless  it  is  known  that 
some  part  has  changed  from  its  original  position  and  requires  being 
restored  to  this  position.  To  illustrate  the  importance  of  this  point,  take 
the  matter  of-  changing  the  distance  in  which  the  car  is  stopped,  which 
can  be  accomplished  by  adjusting  D  and  F  in  the  manner  just  described. 
By  this  method  the  stopping  distance  can  be  changed,  but  if  it  is  made 
too  short,  the  passengers  may  get  a  bad  shaking  up,  while  if  it  is  made 
too  long  there  will  be  an  unnecessary  loss  of  time.  The  engineers  of  the 
elevator  builders  know  as  much  as  anyone  about  the  proper  adjustment  of 
the  stop-motion  apparatus,  if  not  a  great  deal  more;  and,  generally, 
nothing  can  be  gained  but  probably  a  good  deal  lost  by  trying  to  improve 


ADJUSTMENT  AND  CARE  OF  AUTOMATIC  STOP  VALVES  225 

on  their  work.  The  knowledge  of  how  to  make  these  adjustments  should 
only  be  utilized  in  restoring  the  parts  to  their  original  position  if  for  any 
reason  they  become  displaced. 

While  the  stop-motion  valve  of  Fig.  182  was  shown  only  in  connection 
with  a  vertical  machine,  it  can  be  used  just  as  well  with  the  horizontal 
cylinder,  and  in  like  manner  the  stop  valve  shown  with  the  latter  type  of 
machine  can  be  used  with  the  vertical  cylinder.  The  adjustment  of  the 
latter  type  of  valve  is  effected  in  the  same  way  as  that  of  the  Whit- 
tier  horizontal  machine;  that  is,  by  changing  the  position  of  the  stops 
that  are  moved  by  the  operating  arm  attached  to  the  traveling-sheave 
crosshead.  If  it  is  desired  to  have  the  car  stop  higher  up  at  the  top 
floor,  the  stop  E  E  at  the  end  of  the  machine  is  moved  forward,  the 
distance  moved  being  equal  to  the  additional  travel  required,  divided  by 
the  gear  of  the  machine.  To  cause  the  car  to  run  farther  down  at  the 
bottom  floor,  the  stop  E  E  nearest  to  the  cylinder  is  shifted  back  toward 
the  cylinder  through  a  distance  equal  to  the  required  increase  in  travel 
divided  by  the  gear  of  the  machine. 

There  is  one  difference  between  stop  valves  of  the  type  shown  in  Fig. 
165  and  that  of  Fig.  182,  and  that  is  that  with  the  former  it  is  only  possi- 
ble to  vary  the  point  at  which  the  elevator  car  will  stop,  while  with  the 
latter  not  only  can  the  stopping  point  be  varied,  but  also  the  distance  in 
which  the  car  will  stop.  With  valves  like  that  of  Fig.  165  the  stopping 
distance  can  be  changed  only  by  changing  the  form  of  the  edges  of  the 
valve,  or  of  the  ports  covered  by  the  valve,  so  as  to  vary  the  angular  dis- 
tance through  which  the  valve  must  be  moved  to  stop  the  flow  of  water. 
While  this  might  be  regarded  as  a  point  in  favor  of  the  valve  of  Fig. 
182,  it  is  very  doubtful  if  it  is,  because  if  the  stopping  distance  is  once 
made  right  it  will  always  be  right;  hence,  there  is  no  need  of  providing 
means  for  adjusting  it. 

The  main  valve  used  with  high-pressure  machines  is  the  same  for 
either  the  vertical  or  horizontal  type.  In  almost  every  case  the  pilot- 
valve  design  is  used,  but  occasionally  a  simple  valve  for  hand-rope  or 
hand-wheel  operation  is  installed.  So  far  as  the  main  valve  is  concerned, 
there  is  no  difference  between  the  two  types,  as  can  be  clearly  seen  by 
reference  to  Figs.  174  and  172,  the  first  being  the  simple  hand-rope  op- 
erated valve,  and  the  second  the  more  elaborate  pilot-valve  arrangement. 

THE    PACKINGS. 

All  the  packings  of  the  high-pressure  valve  are  leather  cups,  and  they 
are  removed  or  inserted  by  removing  the  head  and  the  cylinder  linings. 

To  remove  these  cup  packings  it  is  necessary  to  draw  out  the  valve, 
and  this  can  be  easily  done  by  taking  off  the  lower  arm  and  freeing  the 


226  HYDRAULIC  ELEVATORS 

valve  from  the  upper  arm.  The  lower  head  is  then  removed  and  the  parts 
M  and  N,  Fig.  174,  are  drawn  down.  The  stuffing-boxes  of  the  pilot 
valve  and  of  the  motor  piston  rod  can  be  packed  without  removing  any 
parts  except  the  glands.  To  take  out  the  piston  it  is  easier  to  remove  the 
lower  cylinder-head  and  piston-rod  guide  than  the  upper  ones,  as  in  so 
doing  it  is  not  necessary  to  disturb  the  levers  or  the  rods.  The  pilot 
valve  can  be  easily  removed  by  taking  off  the  top  cap,  the  lever  L  and  the 
rod  M.  Whenever  any  work  of  this  kind  is  done  it  is  necessary,  of  course, 
first  to  close  the  hand  valve  in  the  supply  pipe  and  then  drain  the  water 
out  of  the  cylinder  and  pipes.  After  the  work  is  completed  the  supply- 
pipe  valve  is  opened  and  the  air  is  withdrawn  from  the  cylinder  and  pip- 
ing. To  get  all  the  air  out  it  may  be  necessary  to  make  a  few  trips  with 
the  car. 

The  lifting  plunger  is  packed  by  means  of  a  stuffing-box  at  the  end 
of  the  cylinder,  the  construction  of  which  for  both  the  vertical  and  the 
horizontal  machines  was  shown  in  the  illustrations  presented  in  previous 
chapters  on  high-pressure  machines.  Any  kind  of  packing  can  be  used, 
in  these  boxes,  but  plain  hemp  with  tallow  works  as  well  as  can  be  desired, 
provided  it  is  properly  put  in.  As  the  pressure  used  in  the  cylinder  is  high, 
the  packing  must  be  put  in  the  box  evenly  in  order  that  there  may  be  no 
soft  spots,  for  if  there  are,  the  water  will  find  them  and  force  its  way 
through,  although  the  other  parts  may  be  pressed  up  hard.  It  is  necessary 
to  force  the  stuffing-box  gland  up  tight  to  make  a  joint  against  the  pres- 
sure used  (750  pounds),  but  it  is  always  desirable  to  compress  the  packing 
as  little  as  possible  in  order  to  reduce  the  friction,  and  the  extent  to  which 
the  packing  must  be  compressed  to  make  it  tight  depends  in  a  large 
measure  upon  the  evenness  with  which  it  is  placed  in  the  stuffing-box. 
If  it  is  crowded  in  tight  on  one  side  and  is  mushy  on  the  other,  no  amount 
of  tightening  will  keep  it  from  leaking. 

The  cylinder  may  be  packed  with  the  car  at  the  top  of  the  building  or 
at  the  lower  floor.  If  it  is  at  the  upper  floor,  it  must  be  secured  to  the 
overhead  beams  before  the  water  is  withdrawn.  If  it  is  at  the  bottom 
floor,  and  the  traveling  sheave  comes  so  near  to  the  stuffing-box  as  to 
interfere  with  free  working,  the  car  should  be  stopped  a  few  feet  above 
the  floor  and  a  temporary  support  put  under  it.  The  distance  above  the 
floor  at  which  the  car  should  be  held  can  be  determined  by  multiplying 
the  gear  of  the  machine  by  the  additional  room  required  to  get  at  the 
stuffing-box  easily. 

An  accumulator  is  packed  at  the  upper  end,  by  means  of  a  stuffing-box, 
the  same  as  the  lifting  cylinder.  To  do  the  packing  the  water  is  drawn 
out  of  the  cylinder  and  the  hand  valve  in  the  inlet  pipe  is  closed.  When 
the  cylinder  is  empty  the  upper  end  projects  above  the  accumulator 


ADJUSTMENT  AND  CARE  OF  AUTOMATIC  STOP  VALVES  227 

weights,  as  shown  in  Fig.  177,  and  the  stuffing-box  can  be  easily  reached. 
Just  as  much  care  is  required  in  packing  the  accumulator  as  in  packing 
the  lifting  cylinder,  because  they  are  both  subjected  to  the  same  pressure. 
The  stuffing-boxes  of  high-pressure  machines  are  made  deeper  than  those 
with  low-pressure  apparatus,  but  even  with  this  extra  depth  they  can- 
not be  made  tight  and  maintained  tight  unless  the  packing  is  done  with 
care. 


CHAPTER  XXXIV 

STOP  VALVES  USED  WITH  ACCUMULATORS,  GENERAL 
ARRANGEMENT  OF  APPARATUS  IN  HIGH-PRES- 
SURE SYSTEMS;  THE  PUMPS  AND 
THEIR  OPERATION 

The  automatic  stop  valves  used  with  accumulators  are  practically  the 
same  in  action  as  those  used  with  the  lifting  cylinders,  and  require  no 
special  mention  here.  The  lifting  cylinder  stop  valves  are  in  most  cases 
made  so  that  when  they  close  the  inlet,  they  also  nearly  close  the  outlet, 
this  construction  being  used  so  that  the  elevator  car  may  start  up  gradu- 
ally on  the  return  trip,  and  by  the  movement  of  the  plunger  through  the 
first  few  inches  of  its  travel  the  valve  is  opened  to  its  full  extent.  The 
accumulator  valves  differ  from  this  construction  in  being  arranged  so 
that  when  the  inlet  is  closed,  the  outlet  is  left  open,  and  in  like  manner 
when  the  outlet  is  closed,  the  inlet  is  left  wide  open.  The  stops  on  the 
actuating  chain  of  the  accumulator  should  be  set  so  as  to  close  the  inlet 
valve  before  the  plunger  rises  high  enough  to  strike  the  shoulder  at 
the  upper  end  of  the  cylinder,  and  the  outlet  valve  should  be  closed 
before  the  weights  strike  the  lower  buffer  block,  but  in  both  cases  the 
stop  should  be  effected  as  near  to  the  mark  as  possible,  in  order  to  utilize 
as  much  of  the  accumulator  capacity  as  practicable. 

If  the  position  of  the  stop  balls  is  changed,  the  pump  stop  must  also 
be  changed ;  otherwise,  the  pump  will  not  act  in  time  with  the  stop  valve. 
The  adjustment  should  be  so  made  that  the  pump  will  stop  just  before 
the  upper  stop  closes  the  inlet  valve,  and  should  start  up  again  just  after 
the  inlet  valve  has  returned  to  the  central  position.  If  the  pump  stops 
after  the  inlet  valve  is  closed,  there  will  be  a  momentary  rise  in  pres- 
sure in  the  system,  and  if  it  starts  before  the  inlet  opens  there  will  be 
another  momentary  rise,  and  this  should  be  avoided  because  it  will  cause 
irregularity  in  the  motion  of  the  elevator  cars.  The  adjustment  of  the 
pump  stop  is  effected  by  changing  the  length  of  the  rope  that  connects 
the  pump  valve  with  the  weight  lifted  by  the  projecting  shelf  on  the 
accumulator. 

The  auxiliary  air  chamber  which  was  shown  in  Fig.  189  requires 
additional  explanation  in  order  that  the  object  of  its  peculiar  construction 
may  be  clearly  understood.  The  lower  end  of  this  air  chamber  is  closed 
by  a  valve  attached  to  the  lower  end  of  a  copper  float.  The  object  of 
this  valve  is  to  prevent  any  of  the  air  in  the  chamber  from  escaping  into 

228 


STOP  VALVES  USED  WITH  ACCUMULATORS  229 

the  pipe  and  thus  finding  its  way  into  the  elevator-lifting  cylinders.  As 
the  water  pressure  is  so  high,  the  air  chamber  has  to  be  charged  with 
compressed  air,  the  pressure  of  which  is  about  one-quarter  of  the  water 
pressure,  so  that  when  compressed  to  the  latter  pressure  it  fills  about  one-* 
quarter  of  the  upper  end  of  the  air  chamber.  If  the  chamber  were  filled 
with  air  at  atmospheric  pressure  this  would  be  compressed  into  a  space 
at  the  upper  end  of  the  chamber  so  small  as  to  have  little  effect  as  a 
cushion. 

As  the  chamber  is  filled  normally  to  about  one-quarter  of  its  volume 
with  compressed  air,  it  would  be  possible  for  some  of  this  to  escape 
through  the  lower  opening  if  there  should  be  a  sudden  and  great  drop  of 
pressure  in  the  pipes,  which  is  possible  if  there  is  an  instantaneous 
increase  in  the  draft  on  the  pipe  system  or  a  corresponding  decrease  in 
the  supply.  If,  however,  the  lower  end  of  the  chamber  is  provided  with 
a  check  valve,  the  air  cannot  escape  because  the  outflow  of  water  will 
close  the  valve.  It  might  be  asked  if  this  is  the  case  why  not  use  a  simple 
check  valve  and  not  one  attached  to  a  float?  The  answer  is  that  the 
simple  check  valve  will  not  work.  For  example,  suppose  a  simple  check 
valve  is  used  to  close  the  outlet  of  the  air  chamber ;  then  if  there  should 
be  a  sudden  rise  in  pressure  in  the  pipes,  which  could  occur  if  several 
elevators  were  stopped  at  the  same  time,  this  pressure  would  lift  the 
check  valve  and  force  water  into  the  air  chamber  until  the  pressure 
became  equal  to  that  in  the  pipe,  which  might  be,  say,  800  pounds. 
From  this  time  on  the  air  chamber  would  be  useless  because  the  pressure 
in  it  would  be  greater  than  that  in  the  pipe  and  the  check  valve,  there- 
fore, would  remain  closed;  the  cushioning  effect  of  the  air  would  then 
be  lost.  When  the  valve  is  attached  to  the  lower  end  of  a  float  the 
action  is  very  different  because  when  the  level  of  the  water  in  the  air 
chamber  rises  above  a  certain  point  the  float  lifts  the  valve  off  the  seat. 
The  level  at  which  the  water  should  lift  the  valve  is  that  which  corre- 
sponds to  a  pressure  considerably  below  the  normal,  so  that  except  when 
the  pressure  drops  very  greatly  the  valve  is  open  and  the  water  in  the 
air  chamber  can  pass  freely  into  the  pipe.  If,  however,  the  pressure 
drops  low  enough,  the  level  of  the  water  in  the  air  chamber  will  drop 
so  low  that  the  float  will  not  be  able  to  hold  up  the  valve  and  then  it  will 
come  down  on  the  seat  and  prevent  any  further  escape  of  water,  and 
consequently  there  is  no  escape  of  air. 

The  valve  seat  is  a  brass  ring  and  the  valve  itself  is  made  of  hard 
rubber.  It  might  be  supposed  that  hard  rubber  would  not  stand  very 
well  in  a  system  using  such  high  pressure,  but  it  does,  owing  to  the  fact 
that  the  pressure  to  which  the  valve  is  really  subjected  is  simply  the 
difference  between  that  in  the  pipe  and  that  in  the  air  chamber,  which  is 


230 


HYDRAULIC  ELEVATORS 


comparatively  small.  Even  if  the  valve  should  wear  so  as  not  to  make  a 
perfectly  tight  joint  it  would  not  matter,  because  the  water  could  not 
escape  fast  enough  through  the  leak  to  draw  air  with  it. 

GENERAL   ARRANGEMENT. 

The  general  arrangement  of  all  the  apparatus  used  in  a  first-class 
high-pressure  elevator  installation  can  be  explained  by  the  aid  of  Fig. 


FIG.   196 

196  and  the  simplified  diagrams,  Figs.  197,  198  and  199.  Fig.  196  shows 
all  the  apparatus  and  the  way  in  which  the  piping  system  is  arranged, 
but  is  necessarily  not  drawn  to  scale,  and  in  some  cases  the  pipe  lines 
are  drawn  in  less  direct  paths  than  they  would  follow  in  actual  practice, 
in  order  to  avoid  confusion  by  the  frequent  crossing  of  lines.  Only  one 
elevator  is  provided  for  in  the  pipe  connections,  but  any  number  can 
be  used  up  to  the  limit  that  the  pump  is  able  to  supply.  It  will  be 
noticed  that  there  are  two  accumulators,  No.  i  being  arranged  to  stop 
the  pump  when  it  is  full.  No.  2  accumulator  is  provided  with  a  stop 
valve  only,  and  it  is  weighted  so  as  to  be  lifted  with  a  lower  pressure 


STOP  VALVES  USED  WITH  ACCUMULATORS  231 

than  No.  I  in  order  that  it  may  act  as  a  reservoir.  Normally,  this 
accumulator  is  full  of  water,  but  if  at  any  time  the  drain  on  the  system 
is  more  than  the  pump  can  supply,  it  delivers  its  contents  to  the  system 
or  as  much  of  it  as  may  be  necessary  to  make  up  the  deficiency.  When 
the  demand  is  reduced  below  the  capacity  of  the  pump,  accumulator  No. 
2  is  filled  again,  so  as  to  be  ready  to  help  the  pump  when  the  next  heavy 
drain  comes.  This  reserve  accumulator  is  connected  as  near  to  the  ele- 
vator cylinders  as  the  construction  of  the  building  will  permit,  in  order 
to  reduce  the  loss  of  energy  due  to  forcing  the  water  through  the  pipes. 
The  pipe  N,  as  shown  in  the  drawing  is  not  very  short  or  straight,  but 
in  practice  it  is  made  as  short  and  straight  as  practicable. 

THE   PUMPS. 

The  pumps  are  generally  made  so  that  when  they  stop  pumping  to 
the  system  they  do  not  actually  stop  moving;  they  continue  to  run,  but 
the  water  circulates  through  a  by-pass  and  the  steam  valve  is  opened 
just  enough  to  keep  the  piston  moving  very  slowly.  This  arrangement 
is  used  in  order  that  when  the  pump  is  called  upon  it  may  get  under 
full  headway  quickly  and  thereby  avoid  the  possibility  of  a  drop  in 
pressure. 

The  course  of  the  water  from  the  pump  is  indicated  by  arrows  drawn 
in  full  lines;  it  passes  first  through  the  auxiliary  air  chamber  (the  one 
with  the  float-supported  valve)  and  on  reaching  the  junction  K  can  run 
up  the  pipe  /  to  the  accumulator,  or  down  the  pipe  /  to  the  junction  L 
whence  it  can  flow  either  through  N  to  the  No.  2  accumulator  or  through 
M  to  the  main  valve  of  the  lifting  cylinder.  If  there  are  several  elevator 
cylinders  they  can  be  connected  with  the  supply  pipe  /.  Examination 
of  this  piping  will  show  that  if  accumulator  No.  I  is  not  full,  water  may 
pass  into  it  and  also  flow  on  through  the  pipe  /  to  the  pipes  TV  and  M ; 
through  the  first  of  these  it  flows  to  accumulator  No.  2  and  through  the, 
other  to  the  operating  valve  of  the  power  cylinder.  If  the  demand  is 
greater  than  the  pump  can  supply,  wrater  will  flow  out  of  accumulator 
No.  i  to  make  up  the  deficiency,  but  water  will  not  flow  out  of  accumu- 
lator No.  2  unless  the  drain  is  so  great  that  accumulator  No.  I,  together 
with  the  pump,  cannot  keep  the  pressure  up  above  that  for  which  No. 
2  is  adjusted;  in  this  case  the  latter  accumulator  will  also  discharge 
into  the  system.  After  the  water  passes  through  the  operating  valve  it 
flows  through  the  speed  regulator  and  thence  into  the  pipe  E  and  to  the 
lifting  cylinder  (not  shown).  Returning  from  the  lifting  cylinder  it 
comes  through  the  same  pipe  E  and  the  speed  governor  to  the  operating 
valve,  and  through  the  latter  to  the  discharge  pipe,  following  the  path  of 
arrows  a.  At  G  it  can  flow  up  into  the  open  tank  on  the  roof  through 
pipe  Q,  or  into  the  pump-suction  pipe,  or  it  can  flow  down  through  the 


232  HYDRAULIC  ELEVATORS 

pipe  O  into  the  discharge  pressure  tank,  and  thence  through  the  pipe  T 
to  the  pump  suction. 

The  object  of  providing  the  discharge  pressure  tank  is  to  cause  the 
discharge  to  flow  out  so  freely  as  not  to  give  the  car  a  jerky  motion.  If 
this  tank  were  not  provided  the  discharge  would  have  to  pass  to  the  junc- 
tion //  and  then  divide  between  the  pump  suction  and  the  roof  tank, 
going  to  the  latter  through  the  pipe  Q.  The  latter  path  would  offer  con- 
siderable resistance,  as  the  tank  would  be  about  175  feet  high,  and  a 
column  of  water  of  this  hight  cannot  be  forced  upward  suddenly.  The 
discharge  pressure  tank  is  located  in  the  basement,  on  the  same  level  as 
the  discharge  pipe  or  possibly  lower,  and  not  far  from  the  elevator 
cylinders ;  consequently,  the  water  can  flow  into  it  with  comparatively 
little  resistance.  The  actual  result  of  this  arrangement  is  that  the  pres- 
sure discharge  tank  receives  nearly  all  the  water  and  the  roof  tank  serves 
simply  to  keep  the  pressure  constant.  The  pipe  T  is  shown  as  tapping 
the  tank  rather  high  up  in  the  side,  but  in  practice  it  enters  near  the  bot- 
tom so  as  not  to  draw  air  into  the  pumps. 

From  the  tee  5  in  the  discharge  pipe  a  connection  runs  to  the  pilot 
valve  to  actuate  the  motor  piston  that  moves  the  main  valve.  The  dis- 
charge from  the  pilot  valve  runs  to  the  open  tank  shown  to  the  left  of 
the  pressure  tank,  and  from  this  tank  it  is  pumped  by  the  small  pilot- 
return  pump  into  the  suction  of  a  small  extra-high-pressure  pump  that 
is  used  to  lift  safes  and  other  heavy  weights. 

At  the  end  of  pipe  M  is  placed  a  spring-cushion  chamber  to  receive 
and  subdue  the  impact  of  the  stream  of  water  when  the  operating  valve 
is  closed.  .This  spring-cushioning  device  was  described  in  connection 
with  Fig.  192,  and  in  the  present  diagram  the  way  in  which  it  acts  is 
very  clearly  shown.  When  the  flow  of  water  through  the  operating  valve 
is  stopped,  the  current  in  the  pipe  M  will  send  the  water  forward  into 
the  cushioning  chamber,  where  its  momentum  will  be  absorbed  in  pushing 
the  plunger  out  and  compressing  the  springs.  When  the  water  comes 
to  a  state  of  rest,  the  springs  force  the  plunger  back  into  the  cylinder, 
ready  for  the  next  blow. 

The  air  pump  shown  is  not  kept  in  operation  all  the  time;  it  is  used 
only  when  it  is  necessary  to  replenish  air  in  the  pressure  tank,  or  in  the 
air  chambers.  When  the  air  in  the  tank  is  not  sufficient  the  pump  is  set 
in  motion  and  then  the  valve  in  the  air  pipe  is  opened  and  air  is  allowed 
to  flow  into  the  tank  until  the  water  gage  shows  the  level  to  be  at  the 
proper  point. 

ELEVATORS  FOR  HEAVY  SERVICE. 

In  all  large  buildings,  where  there  are  several  elevators,  one  of  them 
is  arranged  so  as  to  lift  heavy  weights,  such  as  safes  or  lar^e  machines. 


STOP  VALVES  USED  WITH  ACCUMULATORS 


233 


This  elevator  is  generally  capable  of  lifting  about  three  times  the  load  of 
any  of  the  other  elevators,  and  as  it  is  only  required  to  do  this  work 
occasionally,  simple  means  are  provided  to  accomplish  the  result.  Thq 
means  consist  in  providing  a  small  pump  that  can  develop  a  pressure 
sufficient  to  lift  the  required  load  and  this  is  connected  with  the  piping  of 
the  elevator  in  such  a  way  that  by  manipulating  hand  valves  the  car  may 
be  caused  to  run  either  up  or  down.  The  arrangement  shown  in  Fig. 
196  is  actuated  as  follows:  If  it  is  desired  to  lift  the  load,  the  valves 
A,  B  and  C  are  closed  and  the  valve  D  is  opened,  then  the  safe-lifting 
pump  is  started  and  the  water  follows  the  path  of  the  dotted  arrows  to 
the  lifting-cylinder  pipe  and  to  the  cylinder,  and  the  car  moves  upward. 
The  velocity  of  the  car  will  be  very  slow.  If  it  is  desired  to  run  the  car 
down,  the  valve  D  is  closed  and  the  valve  A  is  opened;  then  the  water 


-© 

0 


FIG.  197 


©0 

FIG.  198 


from  the  lifting-cylinder  pipe  will  escape  into  the  discharge  pipe  and 
through  it  to  the  pressure  tank.  The  car  can  also  be  run  down  by  open- 
ing the  valve  B  with  A  either  open  or  closed ;  the  speed  will  be  greater  if 
B  is  opened.  It  is  not  actually  necessary  to  close  the  valve  D  in  coming 
down.  From  the  foregoing  it  will  be  noticed  that  when  the  safe  pump 
is  used  to  lift  an  extra  heavy  load,  the  main  operating  valve  is  not  used ; 
in  fact  it  is  cut  out  of  service  by  the  closing  of  the  valve  C,  and  the  move- 
ment of  the  car  is  controlled  entirely  by  the  hand  valves  A,  B  and  D. 

While  the  diagram,  Fig.  196,  shows  very  well  the  general  arrange- 
ment of  the  high-pressure  system  with  only  one  elevator,  it  leaves  con- 
siderable to  the  imagination  when  one  considers  an  extensive  plant  con- 
taining a  large  number  of  elevators  and  a  corresponding  number  of 
pumps  and  accumulators.  To  make  the  arrangement  of  such  an  installa- 
tion clear,  Figs.  197,  198  and  199  are  given.  Suppose  that  a  building  is 
equipped  with  twenty  elevators,  and  assume  that  there  are  four  main 
pumps  and  eight  accumulators.  Such  a  system  can  be  arranged  in  many 
different  ways ;  it  can  be  connected  all  in  one  general  piping  system,  or 


234 


HYDRAULIC  ELEVATORS 


it  may  be  divided  into  two,  four  or  even  more  separate  systems.  Sup- 
pose it  is  divided  into  four  separate  systems,  then  each  one  would  con- 
sist of  five  elevators,  two  accumulators  and  one  pump,  and  these  could  be 
connected  in  the  manner  shown  in  Fig.  197,  in  which  the  circles  E 
represent  the  elevator  cylinders,  P  the  pump,  Ai  the  accumulator  that 
stops  and  starts  the  pump,  and  A  2  the  reserve  accumulator  shown  in 
Fig.  196.  At  each  end  of  the  pipe  line  that  connects  the  elevator  cyl- 
inders is  shown  a  spring  cushion  S  to  subdue  the  water-hammer  effects. 
Four  independent  systems  like  this  could  also  be  made  so  as  to  be  con- 
nected with  each  other  or  disconnected  at  will.  In  Fig.  198  is  shown 
an  arrangement  by  means  of  which  two  of  these  units  could  be  connected 
into  one,  by  simply  providing  the  pipe  connections  H  and  /.  With  the 


0 


00 

FIG.   199 


G4  S 


0 


first  pipe  connection  either  one  of  the  pumps  and  its  accumulator  Ai 
could  be  used  to  supply  the  entire  ten  elevators  on  an  emergency,  and 
by  making  the  connection  /.  Both  the  Ai  accumulators  could  be  put  in 
service,  which  would  be  the  best  arrangement,  as  when  the  pump  capa- 
city is  small  the  accumulator  capacity  should  be  large. 

Fig.  199  shows  how  the  four  units  can  be  arranged  to  be  independent 
if  desired,  or  to  be  connected  two  and  two,  or  three  in  one  system  and 
one  independent,  or  all  four  in  one  system.  The  pipe  connection  H  will 
join  the  two  center  sections,  and  K  and  L  will  connect  the  side  sections 
independent  of  each  other  if  H  is  disconnected.  Many  combinations  can 
be  made  by  means  of  proper  connections  between  the  pipe  lines  A,  B, 
C  and  D.  This  is  also  true  of  the  connections  between  the  A2  accumu- 
lators. This  way  of  arranging  the  piping  is  advantageous  not  because 
any  economy  can  be  gained  by  cutting  up  the  plant  into  several  sections 
(in  fact  this  is  not  advisable  as  a  rule),  but  because  if  there  should  be  a 
breakdown  in  any  part,  the  other  parts  can  be  made  to  take  its  place  while 
repairs  are  being  made.  For  example,  if  one  of  the  pumps  gives  out, 


STOP  VALVES  USED  WITH  ACCUMULATORS  235 

the  pipes  leading  to  it  can  be  closed,  and  the  elevators  it  supplies  directly 
can  be  connected  with  the  remaining  pumps. 

There  are  probably  no  two  elevator  installations  of  large  size  that  are 
arranged  exactly  alike,  and  although  the  differences  between  them  are 
due  to  a  considerable  extent  to  the  notions  of  the  architects  of  the  build- 
ing, the  owners,  the  engineers  and  others  interested,  not  a  small  portion 
of  it  is  due  to  the  difference  in  the  conditions  controlling  the  case,  hence, 
an  arrangement  of  an  installation  precisely  as  shown  in  Fig.  199  might 
be  hard  to  find. 

In  these  last  three  diagrams  only  the  supply  pipes  have  been  shown, 
in  order  to  avoid  confusion  and  to  present  clearly  the  way  in  which  the 
pumps,  the  elevator  cylinders  and  the  accumulators  are  connected  with 
each  other  to  obtain  the  best  results. 


CHAPTER  XXXV 
PLUNGER  ELEVATORS 

CONSTRUCTION   OF   PASSENGER   ELEVATORS   OF   THIS    TYPE;   DETAILS   OF    THE 

CYLINDER  AND  VALVES;    HOW    WEIGHT  OF   PLUNGER 

IS   COUNTERBALANCED 

What  is  commonly  known  as  a  plunger  elevator  is  a  direct-acting 
machine  in  which  the  lifting  plunger  is  located  under  the  center  of  the 
elevator  car  and  attached  directly  to  it.  The  plunger  works  in  a  cylinder 
sunk  into  the  earth  to  a  depth  somewhat  greater  than  the  rise  of  the 
elevator.  When  water  is  forced  into  the  cylinder,  the  plunger  rises 
and  pushes  the  car  upward.  To  make  the  downward  trip  the  water  is 
permitted  to  escape  gradually  from  the  cylinder,  allowing  the  plunger  to 
descend  under  the  influence  of  gravity. 

For  many  years  this  type  of  elevator  has  been  used  for  short  travels, 
but  within  the  last  ten  or  twelve  years  it  has  gradually  come  into  use 
for  higher  rises,  and  at  the  present  time  is  used  in  buildings  where  the 
rise  is  as  great  as  300  feet.  As  the  elevator  car  can  rise  only  as  high 
as  the  plunger  travels,  it  follows  that  when  the  rise  is  300  feet,  the  cyl- 
inder must  extend  down  into  the  earth  several  feet  more  than  300, 
because  when  the  car  is  at  the  top  of  the  elevator  well  the  bottom  end 
of  the  plunger  must  be  some  distance  below  the  top  end  of  the  cylinder. 
Furthermore,  it  is  necessary  to  provide  sufficient  length  of  plunger  to 
carry  the  car  a  short  distance  above  the  upper  floor,  say,  two  feet,  in 
order  to  avoid  running  the  bottom  of  the  plunger  too  high  up  in  the 
cylinder  if  the  elevator  should  overrun  the  upper  limit  of  travel. 

As  a  plunger  elevator  is  a  direct-acting  machine,  the  diameter  of  the 
plunger  need  not  be  large,  unless  very  low  pressure  is  used.  As  a  rule 
the  plungers  are  made  of  6-inch  steel  piping,  which,  when  finished,  has 
an  external  diameter  of  6l/2  inches.  The  cylinder  is  also  made  of  steel 
pipes,  and  of  a  diameter  generally  about  two  inches  greater  than  that  of 
the  plunger.  This  diameter  may  be  reduced  for  elevators  of  small  rise 
and  slow  speed,  but  for  high  lifts  and  high  speeds  it  is  greater,  as  it  is 
necessary  to  provide  sufficient  space  between  the  plunger  and  the  cylin- 
der to  permit  the  water  to  pass  down  when  the  plunger  ascends  without 
absorbing  too  much  power  by  its  friction  against  the  walls  of  the  cylin- 
der and  the  plunger. 

236 


FIG.  200 
OTIS  PLUNGER  PASSENGER   ELEVATOR 


238  HYDRAULIC  ELEVATORS 

The  plunger  passes  through  a  stuffing  box  at  the  upper  end  of  the 
cylinder,  and  is  provided  with  guide  shoes  at  the  lower  end  to  keep  it  in 
line  and  central.  The  well  in  the  ground  in  which  the  cylinder  is  set 
is  made  about  three  or  four  inches  larger  than  the  outside  of  the  cylin- 
der. Any  portion  of  it  that  passes  through  gravel  or  clay  is  lined  with  a 
retaining  casing,  but  portions  that  run  through  rock  are  not  lined.  The 
space  between  the  cylinder  and  the  sides  of  the  well  is  filled  in  with 
sand. 

CONSTRUCTION    OF    THE    PASSENGER    ELEVATOR. 

The  construction  and  general  arrangement  of  a  first-class  passenger 
elevator  of  the  plunger  type  are  indicated  in  Fig.  200,  which  is  an  ele- 
vation of  the  Otis  machine.  This  illustration  is  broken  at  a  point  between 
the  elevator  car  and  the  bottom  of  the  elevator  shaft  in  order  to  reduce  its 
length,  but  the  part  broken  away  would  only  show  the  continuation  of 
the  guides,  plunger,  operating  ropes,  etc. ;  all  the  operating  parts  of  the 
outfit  are  shown  in  the  illustration.  The  car  rests  upon  the  upper  end  of 
the  plunger  P,  and  the  latter  runs  down  into  the  cylinder  C,  the  upper 
end  of  which  projects  above  the  ground  floor.  From  the  top  of  the  car 
a  number  of  ropes  R  extend  upward  and  over  a  sheave  5"  and  thence 
down  to  a  counterbalance  W.  This  counterbalance  serves  to  reduce  the 
pressure  required  to  raise  the  elevator,  and  also  to  reduce  the  compression 
stress  to  which  the  plunger  is  subjected. 

The  pipe  of  which  the  plunger  is  made  weighs  about  22  pounds  per 
foot,  so  that  a  plunger  200  feet  long  will  weight  about  4400  pounds ;  this 
is  more  than  the  car  is  likely  to  weigh,  the  latter  ranging  between  3000 
and  4000  pounds.  If  the  car  weighs,  say,  3600  pounds,  and  the  plunger 
4400  pounds,  the  two  combined  will  weigh  8000  pounds,  and  with  no 
counterbalance  this  weight  would  have  to  be  raised  in  addition  to  the 
load.  Consequently  the  plunger  would  be  subjected  to  a  compression 
stress  of  3600  pounds  plus  the  load  at  the  upper  end,  and  8000  pounds 
plus  the  load  at  the  bottom,  the  stress  increasing  from  top  downward  at 
the  rate  of  22  pounds  per  foot.  With  a  counterbalance  weighing,  say, 
5000  pounds,  the  weight  raised  will  be  reduced  to  3000  pounds  plus  the 
load,  and  as  the  counterbalance  exceeds  the  weight  of  the  car  by  1400 
pounds,  it  will  actually  hold  up  about  one-third  of  the  plunger,  from  the 
upper  end  downward,  when  the  car  is  empty. 

When  the  car  is  at  the  bottom  of  the  shaft  the  plunger  is  immersed  in 
the  water  in  the  cylinder,  consequently  a  portion  of  its  weight  is  bal- 
anced by  the  water  it  displaces.  When  the  car  is  at  the  top  of  the  shaft 
the  plunger  is  out  in  the  air  and  its  weight  is  not  counterbalanced  to 
any  extent  by  the  water.  This  being  the  case,  the  weight  lifted  will  be 
less  when  the  car  is  at  the  bottom  of  its  travel  than  when  at  the  top, 


FIG.  201 


230 


240  HYDRAULIC  ELEVATORS 

the  difference  being  equal  to  the  weight  of  water  displaced  by  the  plunger. 
By  properly  proportioning  the  weight  of  ropes  R,  the  load  lifted  can 
be  made  equal  at  all  points,  for  when  the  car  is  at  the  bottom  of  the  shaft 
these  ropes  will  hang  above  the  car,  and  thus  will  offset  a  portion  of  the 
counterbalance  W ,  while  when  the  car  is  at  the  top  of  the  shaft  the  ropes 
will  hang  above  the  counterbalance  W  and  balance  a  portion  of  the 
weight  of  the  car. 

The  main  valve  for  controlling  the  movement  of  the  car  is  shown  at 
F,  and  the  pilot  valve  at  V .  The  two  valves  A  and  B  are  the  automatic 
stop  or  limit  valves,  A  being  the  top  limit  and  B  the  bottom.  The  valve 
A  is  actuated  by  the  rope  A"  which  pulls  up  the  lever  A'  and  thereby 
closes  the  valve.  This  rope  moves  the  lever  A'  through  the  motion  of 
the  elevator  car.  Looking  at  the  illustration,  it  will' be  seen  that  rope  A" 
runs  over  a  sheave  D  mounted  on  top  of  the  elevator  car,  and  it  can 
also  be  seen  that  when  the  car  approaches  the  upper  limit  of  travel, 
D  begins  to  put  a  bend  in  A"  and  thereby  draws  up  lever  A';  by  the 
time  the  car  reaches  the  upper  floor,  A'  will  be  raised  enough  to  close 
valve  A.  By  this  arrangement  the  valve  is  closed  gradually  and  the  car 
is  as  gradually  brought  to  a  state  of  rest. 

The  valve  B  is  actuated  by  rope  B"  in  precisely  the  same  manner 
that  A  is  operated  by  the  rope  A".  The  rope  B"  passes  over  the  station- 
ary sheave  D'  and  under  the  sheave  D"  located  under  the  car,  and  when 
the  latter  descends  near  enough  to  the  lower  floor,  the  bend  put  in  rope 
B"  by  the  sheave  D"  will  raise  the  lever  B'  and  gradually  close  the 
valve  B. 

The  pressure  water  enters  through  valve  A;  hence,  at  the  top  landing 
the  automatic  stop  arrests  the  movement  of  the  car  by  shutting  off  the 
supply  water.  When  the  elevator  car  descends,  the  discharge  water 
passes  out  through  valve  B;  hence,  the  bottom  limit  valve  stops  the 
descent  of  the  car  by  stopping  the  escape  of  water  from  the  cylinder. 

CONSTRUCTION    OF    CYLINDER. 

The  construction  of  the  upper  end  of  the  cylinder  is  shown  in  Fig. 
201.  This  drawing,  which  is  a  vertical  sectional  elevation  of  the  top 
of  the  cylinder  and  plunger,  also  shows  the  way  in  which  the  plunger  is 
fastened  to  the  under  side  of  the  car,  as  well  as  the  construction  of  the 
plunger.  For  the  purpose  of  reinforcing  the  plunger,  a  steel  cable  B 
is  strung  inside,  both  of  its  ends  fastened  to  a  pin  A,  located  some  dis- 
tance below  the  center  of  the  plunger,  and  the  loop  or  bight,  at  the  top  of 
the  plunger,  is  passed  around  a  tightening  block  O ;  this  block  is  arranged 
so  as  to  be  drawn  up  by  the  bolts  O'  to  put  the  desired  tension  on  the  rope 
B.  The  plunger  D  is  made  of  as  many  lengths  of  piping  of  the  proper 


PLUNGER  ELEVATORS 


241 


size  as  may  be  necessary,  these  being  connected  by  means  of  long  internal 
sleeves  C.  The  plunger  sections  are  turned  true  and  highly  polished, 
and  the  screw  threads  at  the  ends  are  made  with  great  accuracy,  so  as  to 
hold  the  sections  in  perfect  alinement  when  connected.  The  threads  are 
also  made  extra  long,  so  that  the  joints  may  be  as  strong  as  the  other 
parts  of  the  pipe.  For  the  purpose  of  making  the  pipe  sections  come 


.rrH         cm      r  n  n  i 


Pipe  Extension      — 

to  i<  loor 


FIG.    202 


FIG.    203 


together  perfectly  central  when  joined,  the  center  portion  of  the  sleeve 
is  turned  true,  and  the  ends  of  the  pipe  are  bored  to  fit  this  portion; 
when  the  parts  are  screwed  up,  the  turned  central  portion  of  the  sleeve 
slides  into  the  bored-out  ends  of  the  pipes  and  brings  them  into  line, 
so  that  there  is  no  point  around  the  joint  where  one  part  projects  over 
the  other. 


242  HYURAUTLIC  ELEVATORS 

The  top  of  the  cylinder  is  finished  off  with  a  casting  F  screwed  to  the 
top  of  the  upper  section  of  the  cylinder  barrel  E.  On  top  of  the  cylinder 
cap  F  is  mounted  a  stuffing-box  casting  G,  containing  the  usual  packing 
space  T  and  fitted  with  a  compressing  gland  G' ';  the  latter  is  constructed 
so  as  to  form  a  space  surrounding  the  plunger  to  hold  oil,  the  latter  being 
fed  in  from  an  oil  cup  K.  Above  this  oil  reservoir  is  a  recess  in  which 
babbitt  wiping  rings  /  are  placed  for  the  purpose  of  scraping  the  oil  off 
the  plunger  as  it  moves  upward,  and  retaining  it  in  the  space  in  the 
gland  G'. 

In  Fig.  200  it  will  be  noticed  that  buffers  F  are  provided  for  the  car 
to  rest  upon  when  at  the  lower  floor.  Similar  buffers  are  also  provided 
for  the  counterbalance  W  to  rest  on,  to  prevent  running  the  car  up 
against  the  overhead  beams.  The  construction  of  the  car  buffers  is 
shown  in  Fig.  202,  which  is  an  external  view  of  the  upper  end  of  the 
cylinder  taken  at  right  angles  to  Fig.  201.  The  buffer  consists  of  a 
plunger  P  made  of  pipe,  provided  with  a  cast  cap  P'  and  a  rubber 
cushion  P".  The  plunger  P  slides  within  a  cylinder  C,  also  made  of  pipe. 
Within  this  cylinder  there  is  a  spring  that  is  compressed  by  the  plunger, 
the  lower  end  of  the  latter  being  provided  with  a  flat  head  to  press  against 
the  top  of  the  spring.  The  cylinder  C  is  held  in  position  by  a  side  exten- 
sion F,  forming  on  the  top  cylinder  casting  F.  The  nuts  Fr  F"  are 
screwed  on  the  cylinder  C,  the  latter  being  threaded,  and  by  this  means 
the  hight  of  the  buffer  is  adjusted.  To  furnish  additional  support,  so 
that  the  buffer  may  not  be  pushed  down  and  the  thread  of  the  nut  F' 
stripped  if  the  car  should  come  down  unusually  hard,  a  pipe  extension  E 
is  provided,  extending  down  to  the  floor,  or  some  other  firm  support. 
These  buffers  are  set  so  as  to  be  struck  and  compressed  every  time  the 
car  comes  down  to  the  lower  floor,  acting  to  stop  the  motion  gradually. 
If  the  car  descends  at  the  normal  speed,  the  buffer  is  compressed  slightly, 
just  a  trifle  more  than  is  necessary  to  hold  the  unbalanced  portion  of  the 
weight  of  the  car,  but  if  the  car  speed  in  approaching  the  floor  is  exces- 
sive, the  buffers  will  be  compressed  farther,  and  llie  car  will  run  a  few 
inches  below  the  floor. 

PLUNGER  CONSTRUCTION. 

The  construction  of  the  lower  end  of  the  plunger  is  shown  in  Fig. 
203.  The  main  portion  consists  of  a  casting  D'  to  the  upper  end  of  which 
is  screwed  the  lower  end  of  the  plunger.  This  casting  does  not  run  up 
to  the  oil  well  in  the  stuffing  box  with  normal  operation  of  the  eleva- 
tor ;  therefore,  its  surface,  if  of  iron,  would  soon  become  rusty.  On  this 
account  it  is  covered  with  a  brass  casing  D".  At  the  lower  end  of  Df 
spaces  are  cored  out  to  receive  the  guide  shoes  A,  pivoted  at  the  upper 
ends  at  A',  and  held  from  moving  too  far  outward  by  a  ring  C  at  the 


244 


HYDRAULIC  ELEVATORS 


extreme  lower  end  of  the  casting  D'.  Provision  is  made  for  either  three 
or  four  shoes  like  A.  The  springs  B  press  tHe  shoes  out  against  the 
cylinder  and  hold  the  lower  end  of  the  plunger  central. 

The  main  operating  valve  used  with  the  Otis  plunger  elevator  for 
high-grade  passenger  service  is  made  in  several  designs.  The  valve 
shown  in  Fig.  200  is  constructed  as  shown  in  Fig.  204,  the  pilot  valve 
part  being  more  clearly  illustrated  in  Figs.  205  and  206,  drawn  to  larger 
scale.  The  pipe  /  shown  in  Fig.  200  connects  the  inlet  P  of  the  pilot' 
valve  chamber  and  the  inlet  B2  of  main  valve  with  the  supply  pipe, 
through  the  limit  valve  A.  In  like  manner  the  pipe  /  connects  the  outlet 


FIG.  205 


Dowu  Stop 


Up  Start 


FIG.    206 


P'  of  the  pilot-valve  chamber  with  the  discharge,  through  the  limit  valve 
B.  The  inlet  O  on  the  pilot-valve  chamber  is  connected  with  inlet  A'  at 
the  back  end  of  the  main  cylinder  by  means  of  the  pipe  marked  K. 

The  operation  of  the  valve  is  as  follows:  When  the  elevator  is  not 
in  motion  the  valves  are  in  the  position  in  which  they  are  shown  in 
Figs.  204,  205,  and  206.  The  space  between  the  main  valve  pistons  A 
and  B  is  filled  with  pressure  water,  as  it  is  permanently  connected  with 
the  supply  pipe.  The  space  between  the  valve  pistons  D  and  E  is  per- 
manently connected  with  the  supply  through  the  pipe  M,  shown  in  Fig. 


PLUNGER  ELEVATORS  245 

»  / 

200.  The  space  between  the  valve  pistons  B  and  C  is  connected  with  the 
discharge  through  pipe  N.  The  space  back  of  piston  A  is  filled  with 
water  through  the  pipe  connection  running  from  A  to  the  inlet  0  on  the 
pilot-valve  chamber,  and  as  the  pilot  valves  are  closed  this  water  cannot 
escape,  hence  the  valve  A  cannot  move  to  the  left.  If  it  is  desired  to 
run  the  car  upward,  the  operating  lever  G  is  raised  and  the  through 
the  connecting  levers  H  and  /  the  connecting  rod  K  is  drawn  to  the 
right,  and  the  valve  T ,  Fig.  205,  is  thereby  opened,  and  the  water  back 
of  the  valve  piston  A  escapes  into  the  pilot-valve  chamber  through  the 
inlet  O  and  out  through  valve  T'  and  valve  R'  to  the  outlet  port  Pr, 
following  the  path  through  the  outlet  X.  As  the  pressure  on  the  right- 
hand  side  of  the  piston  A  is  greater  than  that  on  the  left-hand  side  of  B, 
the  main  valves  will  be  moved  to  the  left,  and  pressure  water  will  pass 
by  the  valve  piston  D  and  into  the  pipe  connecting  with  the  lifting 
plunger  cylinder,  and  the  car  will  be  moved  upward. 

The  movement  of  the  main  valves  to  the  left  will  cause  the  pilot  valve 
to  move  in  the  same  direction,  as  the  valve  rod  F,  through  the  con- 
necting rod  F',  will  carry  the  lever  F"  to  the  left,  swinging  the  fulcrum 
H'  downward,  and,  through  the  link  H,  moving  the  rod  K.  The  move- 
ment of  the  main  valves  to  the  left  will  continue  until,  through  the  motion 
of  the  lever  F" ,  the  pilot  valve  has  been  carried  far  enough  to  the  left 
to  close  the  valve  T ;  then  the  outflow  of  water  from  behind  the  piston  A 
will  cease,  and  the  main  alve  will  move  no  farther.  In  this  respect  the 
operation  is  the  same  as  that  of  every  type  of  pilot  valve  that  has  been 
explained  in  preceding  chapters.  The  distance  through  which  the  main 
valves  will  move  is  evidently  proportional  to  the  distance  through  which 
the  pilot  valve  is  moved  by  the  lever  G;  for  the  movement  of  the  main 
valve  must  be  sufficient  to  return  the  pilot  valve  to  the  closed  position,  and 
no  more. 

THE   PILOT  VALVE. 

Although  the  operation  of  this  pilot  valve  is  the  same  in  general  as 
that  of  all  other  pilot  valves  insofar  as  it  has  been  explained,  it  possesses 
one  feature  not  found  generally  on  the  pilot  valves  of  the  cable  types  of 
hydraulic  elevator.  It  will  be  noticed  that  there  are  apparently  two  pilot 
valves,  V  and  V .  In  reality  only  F  is  a  pilot  valve,  the  valve  V  being 
supplied  for  the  purpose  of  controlling  the  distance  in  which  the  elevator 
can  be  stopped.  Referring  to  Fig.  204  it  can  be  seen  that  when  lever 
F"  is  moved  to  the  left,  as  the  main  valve  opens  to  let  pressure  water 
flow  into  the  lifting  cylinder,  the  upper  end  of  F"  carries  lever  K'  to  the 
right,  and  this  moves  valve  V  to  the  right  while  valve  V  is  moved  to  the 
left.  This  is  the  action  when  the  pilot  is  moved  to  start  the  car,  but  when 
it  is  desired  to  stop  the  car  on  the  upward  trip,  lever  G  is  moved  down- 


246  HYDRAULIC  ELEVATORS 

ward,  and  then  the  pilot  valve  V  is  moved  to  the  left  and  valve  T  is 
opened,  allowing  pressure  water  from  the  inlet  P  to  pass  through  valves 
R  and  T  into  the  pilot-valve  chamber  and  through  the  outlet  O  to  the 
inlet  A'  at  the  back  end  of  the  main  valve,  thereby  equalizing  the  pres- 
sures on  both  sides  of  the  piston  A;  the  unbalanced  pressure  on  the  left- 
hand  side  of  B  will  then  force  the  main  valves  to  the  right  and  shut  off 
the  flow  of  pressure  water  from  the  supply  pipe  into  the  lifting  cylinder. 

Looking  now  at  Fig.  205  it  will  be  seen  that  when  the  pilot  valve  V 
is  in  the  central  position,  valve  V  will  also  be  central,  and  the  end  valves 
L  and  L'  will  be  opened,  so  that  water  can  flow  freely  from  inlet  P 
to  port  U  without  passing  through  port  Uf,  and  also  flow  out  from  the 
passage  X  to  P'  without  going  through  X' .  The  valve  S  in  port  U' 
checks  the  flow  of  water  so  that  a  much  smaller  quantity  can  pass  through 
U'  than  through  U;  hence  if  valve  L  is  closed,  so  that  water  has  to  flow 
in  through  U',  it  will  require  much  more  time  to  fill  the  space  back  of  the 
main  valve  piston  A  than  if  the  water  were  flowing  through  U.  Now 
when  lever  G  is  raised  to  send  the  car  upward,  the  movement  of  the  main 
pistons  to  the  left  will  carry  valve  V  to  the  right,  and  thus  carry  valve 
L  into-  the  opening  through  which  water  flows  into  port  U;  therefore, 
when  the  pilot-valve  lever  G  is  depressed  to  stop  the  car,  the  main  valve 
will  not  move  back  rapidly  to  the  stop  position,  in  which  it  is  drawn, 
because  the  water  flowing  in  from  P  to  move  the  main  valve  has  to  pass 
through  the  restricted  passage  U;  therefore  the  return  movement  of  the 
main  valve  is  much  slower  than  the  forward  or  starting  movement. 

It  is  evident  that  by  adjusting  the  opening  through  the  valve  5  the 
flow  of  water  through  U'  can  be  made  as  slow  as  desired.  As  will  be 
seen  from  Fig.  206  the  valves  R  R'  and  S"  Sf  are  simply  plugs  that  can 
be  adjusted  for  any  amount  of  opening  and  held  permanently  in  that 
position.  The  object  of  using  these  valves  and  the  valve  V  is  to  provide 
positive  means  to  control  the  rapidity  with  which  the  elevator  can  be 
stopped.  In  a  plunger  elevator,  if  the  car  is  stopped  very  quickly  on 
the  up  trip,  the  momentum  of  the  upward  moving  car  and  the  downward 
moving  counterbalance  will  tend  to  continue  the  car  travel  and  as  a  result 
the  plunger  will  move  away  from  the  water  in  the  cylinder.  As  soon 
as  the  car  stops,  it  will  run  back  and  stop  suddenly  when  the  plunger 
strikes  the  water.  If  the  car  is  coming  down  and  the  operator  stops 
it  suddenly,  the  momentum  of  the  car  and  its  load  will  tend  to  buckle  the 
plunger.  As  it  is  not  possible  for  an  operator  to  judge  just  how  fast  to 
move  the  operating  lever  to  make  as  quick  a  stop  as  can  be  made  with- 
out causing  the  plunger  to  leave  the  water  on  the  up  trip,  or  to  buckle 
on  the  down  trip,  it  is  necessary  to  provide  means  for  controlling  the 
rapidity  of  stopping,  and  the  valves  described  are  the  means  provided 


247 


248 


HYDRAULIC  ELEVATORS 


for  this  purpose.  With  this  arrangement  of  valves,  the  operator  can 
make  as  slow  a  stop  as  he  may  desire,  but  if  he  moves  the  lever  G 
instantly  to  the  stop  position,  the  elevator  will  be  brought  to  a  state  of 
rest  gradually  in  the  shortest  practical  time,  but  no  sooner.  The  time 
or  distance  in  which  the  car  will  be  stopped  can  be  varied  as  desired  by 
changing  the  adjustment  of  the  valves  ^  S' .  The  valves  R  Rf  are  pro- 
vided to  prevent  too  rapid  a  start. 

ANOTHER  TYPE  OF  STARTING  VALVE. 

Another  design  of  starting  valve  is  shown  by  Fig.  207.    This  arrange- 
ment is  provided  with  more  simple  pilot  valves  and  there  are  no  adjusting 


FIG.   208 


valves  to  regulate  the  rapidity  of  acceleration  in  starting.  The  plug 
valves  A  B  are  for  the  purpose  of  adjusting  the  stopping  distance.  In 
starting,  water  can  flow  directly  into  the  passage  D  or  D'  as  the  case 
may  require,  without  passing  through  the  holes  connecting  these  pas- 
sages with  C  and  Cr  which  are  controlled  by  the  plugs  A  and  B.  This  is 
possible  because  the  valve  V  is  in  the  central  position,  but  in  stopping, 
this  valve  is  shifted  in  one  direction  or  the  other,  just  as  in  the  valves  of 
Fig.  205,  and  the  water  then  has  to  flow  from  the  passage  C  to  D 


PLUNGER  ELEVATORS 


249 


through  the  hole  that  is  throttled  by  plug  A,  or  from  C  to  D'  through 
the  hole  throttled  by  B.  In  this  design  outside  piping  is  not  used  to  con- 
nect the  pilot  valve  with  the  main  valve ;  passages  are  cored  in  the  cast- 
ings, as  shown  clearly  in  the  drawing.  By  comparing  this  valve  with 
Fig.  204  the  operation  of  every  part  will  become  perfectly  clear.  If  the 
lever  G,  Fig.  207,  is  raised,  K  will  be  shifted  to  the  left  through  the 
action  of  K" ,  because  F"  holds  K  stationary.  If  G  is  moved  downward, 


FIG.  209 

K  will  be  shifted  to  the  right.  Thus  V  will  be  left  in  the  central  position 
when  G  is  moved  to  start  the  elevator  running  in  either  direction.  As 
soon,  however,  as  the  main  valve  starts  to  move,  V  will  be  shifted  from 
the  central  position  because  the  upper  end  of  F"  moves  K'. 

The  main  valve  of  Fig.  204  has  five  pistons,  while  that  of  Fig.  207 
has  only  four.  The  former  valve  could  also  be  made  with  four  pistons 
by  simply  exchanging  the  supply  and  exhaust  pipes. 

The  latest  design  of  operating  valves  used  with  the  Otis  plunger  is 
shown  in  Fig.  208.  An  enlarged  view  of  the  pilot  valve  and  of  the  valve 
V  is  given  in  Fig.  209.  The  principal  difference  in  the  main  valve  is  that 
it  is  divided  into  two  sections,  these  being  located  in  separate  cylinders, 
one  below  the  other.  On  account  of  this  construction,  one  more  piston, 
B',  is  required,  but  on  the  other  hand  the  pistons  A  and  B  are  of  much 


250 


HYDRAULIC  ELEVATORS 


smaller  diameter  than  in  Fig.  204.  The  only  function  of  these  pistons 
is  to  move  the  valves  and  on  this  account  A  can  be  made  considerably 
smaller  than  the  valve  pistons  C,  D,  E,  as  all  that  is  necessary  is  that  the 
area  of  A  be  sufficiently  in  excess  of  that  of  B  to  provide  all  the  force 
necessary  to  move  the  valves,  and  this  difference  in  area  is  obtained  by 
reducing  the  diameter  of  B  to  the  proper  point.  Although  two  valve 
cylinders  are  provided,  they  are  both  of  smaller  diameter  than  the  single 
one  of  Fig.  204  and  in  addition  the  length  of  the  valve  is  considerably 
reduced. 

The  pipe  O'  connects  the  pilot-valve  chamber  at  O  with  the  lower4 
valve  cylinder  at  O".  The  inlet  /'  between  the  pistons  A  and  B  is  per- 
manently connected  with  the  supply  pipe  so  that  the  full  tank  pressure  is 
always  in  this  space;  hence,  when  the  pilot  valve  is  moved  so  as  to 


FIG.  210 
THE  PLUNGER   VALVE 

connect  O'  with  the  discharge,  the  piston  will  move  to  the  left,  as  the 
pressure  on  the  right-hand  side  of  A  is  greater  than  that  on  the  left- 
hand  side  of  B}  but  if  O"  is  connected  with  the  supply  pipe,  through  the 
opposite  movement  of  the  pilot  valve,  the  pressure  on  both  sides  of  A 
will  be  equal,  while  B  will  be  subjected  to  the  full  tank  pressure  on  the 
left-hand  side,  and  only  to  the  atmospheric  pressure  on  the  right-hand 
side;  therefore,  the  valves  will  move  to  the  right.  The  construction  of 
the  pilot  valve  and  the  valve  V  is  clearly  shown  in  Fig.  209.  Looking 
at  the  sectional  view  it  can  be  seen  that  about  the  only  difference  between 
it  and  Fig.  205  is  that  the  plug  valves  R  Rr  are  not  used.  Experience 
has  shown  that  they  can  be  omitted,  as  gradual  acceleration  can  b$ 
effected  in  several  other  ways,  as  for  example,  by  varying  the  distance 
between  the  valve  L  and  L'  so  as  to  throttle  the  passage  into  U  or  X 
more  or  less,  as  may  be  required,  or  by  varying  the  diameter  of  the 
spacing  sleeves  between  these  valves.  The  external  appearance  of  this 


PLUNGER  ELEVATORS 


251 


valve  is  shown  in  Fig.  210.  This  illustration  also  serves  to  make  per- 
fectly clear  the  construction  of  the  levers  F" ,  H,  ] ,  K,  K' ,  etc.  The  lever 
K'  is  actuated  by  an  extension  of  F"  above  the  pivot  on  which  this  lever 
swings ;  hence,  in  starting,  K"  remains  stationary. 


FIG.  211 


FIG.    212 


The  main  pipe  connections  are  made  with  the  upper  cylinder,  as 
this  one  contains  the  valve  proper,  the  lower  cylinder  being  simply  a 
motor  cylinder.  In  Fig.  210  only  the  supply  pipe  connection  S  and  the 


252  HYDRAULIC  ELEVATORS 

lifting  cylinder  connection  C  are  shown,  the  discharge  pipe  connection 
being  on  the  other  side.  The  position  of  these  pipe  connections  is  varied 
to  suit  the  location  of  the  piping  in  each  particular  case,  and  this  location 
is  governed  by  the  shape  of  the  building  and  the  location  of  the  pumps, 
tanks,  etc.  Fig.  208  shows  the  three  pipe  connections  all  on  the  same 
side.  In  most  cases  the  supply  and  discharge  are  more  likely  to  be  on 
one  side  and  the  cylinder  connection  on  the  other.  The  two  inlets  O 
and  O"  are  connected  with  each  other,  and  the  inlet  /'  is  connected  with 
the  supply  pipe. 

AUTOMATIC    STOP    VALVES. 

The  construction  of  the  automatic  stop  valves  A  and  B,  of  Fig.  200,  is 
very  simple.  Two  of  these  valves  of  different  design  are  shown  in  Figs. 
211  and  212.  In  Fig.  211,  the  water  enters  through  inlet  E  and  passes 
out  through  the  opening  F,  whether  the  valve  is  connected  in  the  supply 
or  the  discharge  pipe;  in  Fig.  200  it  will  be  noticed  that  in  both  valves 
A  and  B  the  water  flows  in  through  the  top  pipe.  The  piston  A  serves 
to  balance  the  pressure  on  top  of  piston  B,  and  also  keeps  the  water  from 
passing  out  through  the  upper  end  of  the  valve.  The  piston  C  acts  to 
prevent  the  escape  of  water  from  the  lower  end.  When  the  elevator 
is  going  up  the  valve  in  the  supply  pipe  is  in  the  position  in  which  it  is 
shown  in  Fig.  211,  and  the  valve  in  the  discharge  pipe  is  raised  so  that 
piston  B  is  some  distance  above  the  upper  edge  of  port  P.  When  the 
piston  B  is  in  this  position,  piston  C  is  just  below  port  P,  so  that  if  any 
part  of  the  discharge  pipe  beyond  F  is  higher  than  P  the  water  in  it 
cannot  flow  out  through  the  bottom  of  the  valve  casing.  To  catch  any 
drip  that  may  occur,  the  drain  pipe  JV  is  provided,  and  the  opening  M 
is  for  cleaning  out  this  connection  if  it  becomes  clogged  up.  When  the 
valve  piston  B  is  above  the  ports  P,  the  water  within  the  lifting  cylinder 
cannot  escape;  hence,  as  water  flows  in  through  the  open  supply  pipe 
the  plunger  is  forced  upward  and  the  elevator  car  is  raised.  When  the  car 
reaches  the  upper  floor,  the  limit  valve  A,  Fig.  200,  is  closed  by  lifting 
piston  B  above  the  ports  P,  and  the  car  stops.  As  it  is  necessary  that  the 
car  be  stopped  gradually,  the  upper  edges  of  the  ports  P  are  made  to 
incline  toward  each  other,  so  as  to  gradually  stop  the  flow  of  water 
When  the  car  is  stopped  on  the  down  trip  at  the  lower  floor  by  the  action 
of  the  stop  valve  B,  Fig.  200,  the  action  is  the  same  as  described  for  the 
up  stop,  with  the  exception  that  instead  of  stopping  off  the  flow  of  pres- 
sure water  into  the  lifting  cylinder,  the  discharge  of  water  from  the 
cylinder  is  stopped. 

There  is  a  slight  difference  between  the  arrangement  of  the  actuating 
lever  /  in  Fig.  211  and  the  corresponding  lever  A'  in  Fig.  200.  In  the 
latter  the  lever  is  pivoted  between  the  ends  and  the  valve  connecting  rod 


PLUNGER  ELEVATORS  253 

is  connected  with  one  end.  When  the  valve  is  so  arranged,  the  piston  is 
depressed  to  stop  the  elevator,  while  in  Fig.  211  it  is  raised.  To  arrange 
the  valve  so  as  to  stop  by  depressing  piston  B,  it  is  necessary  that  the 
latter  be  raised  sufficiently  to  rest  above  the  inlet  E  when  the  valve  is 
opened ;  then  if  it  is  depressed  below  E  the  flow  of  water  is  stopped.  To 
make  the  valve  operate  in  this  way  the  cylinder  lining  G  is  made  longer 
so  as  to  extend  up  above  the  inlet  E,  and  the  ports  P  are  cut  opposite  this 
inlet.  The  piston  B  is  raised  so  as  to  rest  just  below  the  bottom  of  ports 
P  when  the  valve  is  closed  and  lever  /  is  in  the  position  shown;  then 
when  the  valve  is  opened,  by  lifting  it,  the  piston  B  is  carried  above  the 
ports  P  and  the  piston  A  is  raised  to  the  top  of  the  valve  cylinder.  The 
valve  piston  C  remains  in  the  same  position  as  in  Fig.  211.  When  this 
change  is  made,  the  cylinder  linings  G  and  H  are  virtually  interchanged, 
although  the  same  linings  are  not  used;  H  is  made  long  enough  to  con- 
tain the  ports  P,  and  G  is  shortened  so  as  not  to  project  up  above  the 
lower  edge  of  the  outlet  F.  The  arm  K  that  carries  lever  /  is  secured 
to  the  valve  casing,  so  that  it  may  be  moved  around  into  any  radial  posi- 
tion that  may  be  desired.  The  arm  K  is  provided  with  a  clamping  ca,p, 
and  the  two  parts  are  bored  to  fit  the  upper  neck  L  of  the  valve  casing, 
so  that  in  whatever  position  the  arm  may  be  set  it  will  come  into  line 
with  the  valve  rod  D  when  the  cap  is  tightened  up  by  the  clamping  bolts. 
The  valve  shown  in  Fig.  212  differs  from  that  of  Fig.  211  in  the  con- 
struction of  the  piston  B  and  the  cylinder  lining  G.  The  latter  is  a  short 
tube  without  ports,  these  being  formed  in  the  upper  portion  B'  of  piston 
B.  When  the  valve  is  fully  opened,  B'  drops  to  the  position  in  which 
it  is  here  shown,  and  the  ends  pass  nearly  out  of  the  lining  G.  When  the. 
valve  is  closed  the  piston  B  is  raised  until  the  cup  packing  enters  the 
lower  end  of  lining  G  far  enough  to  make  a  joint  and  stop  the  flow  of 
ater.  The  ports  cut  in  B'  are  V-shaped,  so  that  as  the  valve  moves 
upward,  the  flow  of  water  is  gradually  stopped. 

THE    PISTON    VALVES. 

The  construction  of  the  piston  valves  is  clearly  shown  in  Fig.  212. 
The  arm  K  that  supports  the  actuating  lever  /  is  made  with  two  pivot 
holes  R  Rr,  in  order  to  adjust  the  leverage  of  /  for  different  movements 
of  the  actuating  ropes.  The  travel  of  these  ropes  can  also  be  adjusted 
by  varying  the  point  of  attachment  of  one  and  the  position  of  the  lever 
/  for  the  other.  The  effort  required  to  move  the  limit  valves  can  also  be 
varied  by  means  of  the  two  pivot  holes  R  Rr,  for  if  the  one  nearest  the 
valve  is  used,  the  lift  of  the  actuating  rope  will  be  increased  and  the  pull 
will  be  reduced.  With  small  valves,  as  the  frictional  resistance  is  less, 
the  lever  /  can  be  pivoted  in  the  hole  R,  and  then  less  movement  of  the 
actuating  rope  will  be  required. 


CHAPTER  XXXVI 

OPERATION  OF  MAIN  AND  PILOT  CONTROL  VALVES; 

COMPARISON  OF  DIFFERENT  CONTROL  AND 

AUTOMATIC  STOP  VALVES 

The  general  arrangement  of  the  main  valve  and  pilot,  the  automatic 
stop  valves,  the  actuating  ropes,  etc.,  of  the  latest  type  of  Otis  passenger 
plunger  elevators  is  shown  in  the  vertical  elevation,  Fig.  213.  This 
drawing  is  made  to  scale,  and  shows  all  the  parts  in  their  true  propor- 
tion. The  reference  letters  are  the  same  as  in  Fig.  200,  so  that  the  dif- 
ference between  the  two  arrangements,  as  well  as  the  difference  in  the 
design  of  the  valves,  can  be  easily  distinguished.  The  automatic  stop 
valves  A  and  B  are  of  the  design  shown  in  Fig.  211  and  the  main  valve 
is  the  type  shown  in  Fig.  208.  The  flow  of  water  through  the  entire 
system  is  indicated  by  the  arrows.  When  the  valve  is  set  to  ascend,  water 
flows  in  from  the  supply  pipe  through  the  stop  valve  A  to  the  inlet  at 
the  right-hand  end  of  the  upper  cylinder  of  the  main  valve.  Passing 
through  the  valve  the  water  enters  the  vertical  pipe  leading  from  the 
central  outlet  of  the  valve  chamber,  enters  the  upper  end  of  the  lifting 
cylinder,  and  forces  the  plunger  upward,  thus  lifting  the  car.  When  the 
valve  is  set  to  come  down,  the  water  in  the  lifting  cylinder  flows  out  and 
down  through  the  vertical  pipe  to  the  center  of  the  valve  chamber, 
through  the  valve  to  the  left  side  outlet,  and  thence  through  the  pipe  to 
and  through  stop  valve  B.  In  Fig.  200  the  two  automatic  stop  valves 
are  made  so  that  the  water  flows  through  them  from  top  to  bottom,  but 
in  Fig.  213  the  water  enters  both  valves  at  the  bottom  and  passes  out 
at  the  top. 

The  levers  of  the  valves  A  and  B  are  arranged  as  in  Fig.  211.  The 
rope  that  actuates  valve  A  runs  over  and  under  the  pair  of  sheaves  shown 
just  under  the  floor  of  the  elevator  pit.  «  This  arrangement  is  shown  in 
order  to  be  able  to  give  a  side  view  of  lever  A'  and  rope  A" ;  in  practice 
lever  A'  would  be  rotated  around  far  enough  to  permit  the  rope  to  run 
up  in  a  straight  line  back  of  the  elevator  car.  The  upper  end  of  rope  A" 
is  secured  to  one  of  the  overhead  beams,  as  shown  in  Fig.  214,  which 
shows  the  top  of  the  elevator  well,  with  the  overhead  sheave  over  which 
the  counter-balance  ropes  run,  and  also  the  arrangement  for  holding 
the  upper  ends  of  the  pilot  valve  operating  ropes.  The  rope  B" ,  that 
actuates  lever  B'  of  valve  B,  runs  up  and  over  a  stationary  sheave  and 

254 


255 


FIG.  213 
GENERAL   ARRANGEMENT   OF    OTIS    PLUNGER    ELEVATOR 


256 


HYDRAULIC  ELEVATORS 


thence  under  a  sheave  attached  under  the  car,  near  the  right-hand  side. 
In  this  case  the  stationary  sheave  is  necessary  to  prevent  the  rope  from 
pulling  sidewise  on  lever  B'  when  the  car  approaches  the  bottom  floor. 
The  rope  B"  is  secured  to  the  overhead  beams  at  one  side. 

The  pilot  valve  is  actuated  by  the  ropes  G'  G" ,  one  side  of  which  is 


FIG.  214 

secured  to  the  end  of  the  operating  lever  G.  This  arrangement  is  of  the 
standing-rope  class,  but  it  is  slightly  modified,  the  modification  being 
necessary  by  reason  of  the  fact  that  the  lower  supporting  sheaves  H 
cannot  be  run  down  below  lever  G}  on  account  of  the  space  being  taken 
up  by  the  valves  and  piping.  The  stretches  of  rope  G'  and  G"  are  a 
single  continuous  rope,  the  two  ends  of  which  are  secured  at  the  top 
of  the  elevator  well  to  a  tightening  lever  N,  the  weight  W  being  set  to 
put  the  proper  tension  on  the  ropes.  Coming  down  to  the  car,  these 
ropes  pass  around  the  two  sheaves  S,  5\  carried  in  a  frame  M  mounted 
upon  the  car  and  connected  with  the  car  lever  L  through  rod  L".  The 


MAIN  AND  PILOT  CONTROL  VALVES 


257 


rope  G'  runs  under  the  sheave  Sf  and  over  the  sheave  S,  thence  down 
to  lever  G,  and  passes  under  the  sheave  H"  located  below  lever  G. 
This  part  of  the  apparatus  is  more  fully  shown  in  Fig.  215,  which  is  a 
side  view  of  the  lower  part  of  Fig.  213.  Passing  up  from  the  right  side 
of  sheave  H",  the  rope  becomes  G" ,  and  upon  reaching  the  sheaves  H, 
passes  over  the  one  on  the  right-hand  side  and  under  the  one  on  the 
left,  and  then  runs  up  and  over  sheave  S'  and  under  sheave  S,  thence 
up  the  elevator  well  to  the  tension  lever  N. 

Keeping  in  mind  the  arrangement  of  the  ropes  just  described,  it  can 
be  seen  that  if  the  car  lever  L  is  moved  to  the  right,  the  connecting  rod 


FIG.  215 

L"  will  move  to  the  left,  and  swing  the  frame  M  clockwise,  so  that 
sheave  S  will  move  downward  and  S'  upward.  As  rope  G"  passes  over 
sheave  S'  it  will  be  drawn  up  and  G'}  which  passes  under  S',  will  be  let 
out,  the  result  being  that  the  pilot-valve  lever  G  will  be  raised.  The 
sheave  H"  and  the  extension  of  the  ropes  below  H  complicate  the 
arrangement  slightly,  but  do  not  change  the  principle  of  operation  in 
the  least. 

SIMPLE  TYPE   OF  OTIS  FREIGHT   ELEVATOR  WITH    HAND   ROPE   CONTROL. 

The  general  arrangement  of  a  simple  type  of  Otis  plunger  elevator  is 
shown  in  Fig.  216,  which  is  a  vertical  elevation  of  a  freight  elevator  pro- 
vided with  hand-rope  control.  The  operating  valve  is  shown  with  a  long 
lever  to  the  end  of  which  the  hand  rope  is  attached.  The  valve,  as  will 
be  seen,  is  very  simple,  the  supply  water  reaching  it  through  the  pipe 
A,  which  enters  the  upper  end  of  the  valve  cylinder.  From  the  lower 


FIG.  216 


MAIN  AND  PILOT  CONTROL  VALVES  259 

end  of  the  cylinder  a  pipe  B  connects  with  the  upper  end  of  the  plunger 
cylinder,  and  through  this  pipe  the  water  enters  when  the  elevator 
ascends,  and  escapes  when  it  descends.  The  escaping  water  passes  out 
of  the  main  valve  through  the  bottom,  and  is  carried  off  to  the  discharge 
tank  through  the  pipe  D.  The  operating  lever  L  is  used  when  the  car 
runs  at  very  slow  speed,  as  is  generally  the  case  in  buildings  of  three  or 
four  floors.  For  higher  velocities  of  car  it  is  necessary  to  substitute 
for  the  lever  L  other  means  of  moving  the  valve,  whereby  greater  move- 
ment of  the  operating  hand  rope  is  required  to  open  and  close  the  valve. 
If  such  means  were  not  provided,  the  starting  and  stopping  would  be 
entirely  too  rapid.  If  the  car  speed  is  moderate,  say  100  feet  per  minute, 
the  valve  is  operated  by  means  of  a  rack  and  pinion,  in  precisely  the 
same  way  as  the  hand-rope  operated  valves  already  described  as  being 
used  with  cable  hydraulic  elevators. 

In  some  cases  freight  elevators  are  arranged  so  as  to  carry  passengers 
also,  and  on  that  account  are  run  at  a  higher  speed,  and  occasionally 
passenger  elevators  in  buildings  where  economy  of  construction  is  con- 
sidered are  arranged  to  be  controlled  by  a  simple  hand-rope  operated 
valve.  For  such  installations,  the  simple  rack-and-pinion  arrangement  is 
not  satisfactory  because  it  will  close  the  valve  with  too  small  a  movement 
ef  the  hand  rope.  For  such  service  the  valve  is  made  with  a  double  set 
of  gears,  the  pinion  that  meshes  with  the  rack  being  mounted  upon  a 
shaft  that  carries  a  larger  gear,  and  that  in  turn  meshes  with  a  second 
pinion  that  is  mounted  upon  the  hand-rope  sheave  shaft. 

When  a  lever-operated  valve  is  used,  the  travel  of  the  hand  rope 
is  varied  by  varying  the  length  of  the  lever  L,  which  is  made  about  3 
feet  long  for  very  low  speeds  and  as  much  as  7  feet  for  the  highest 
speeds.  When  the  lever  is  3  feet  long,  the  movement  of  the  hand  rope 
required  to  make  a  stop  on  the  up  trips  is  about  15  inches,  and  on  the 
down  trips  about  10  inches.  With  the  longest  lever,  about  7  feet,  the 
rope  movement  to  make  a  stop  on  the  up  trips  is  about  3  feet,  and  on  the 
down  trips  about  30  inches.  With  the  single-geared  rack-and-pinion 
the  rope  travel  required  to  stop  the  car  is  about  5  feet,  which  can  be 
varied  to  some  extent  by  changing  the  diameter  of  the  hand-rope  sheave, 
say  from  4  to  7  feet.  When  a  double-reduction  gear  is  used  the  rope 
travel  varies  from  about  9  to  18  feet,  according  to  the  car  speed.  If  only 
the  manipulation  of  the  hand  rope  by  the  operator  were  considered,  it 
would  not  be  so  important  to  vary  the  movement  of  the  hand  rope  with 
the  speed  of  the  car,  because  with  a  little  practice  an  operator  could 
learn  just  how  to  manipulate  the  rope  to  make  satisfactory  stops,  but  the 
car  is  also  stopped  automatically  at  the  top  and  bottom  landings  by  the 
movement  of  the  hand  rope  and  this  movement  is  effected  by  the  car 


260  HYDRAULIC  ELEVATORS 

itself;  hence,  the  travel  of  the  hand  rope  required  to  stop  the  car  must 
be  made  to  conform  to  the  car  speed. 

In  Fig.  216  the  elevator  is  represented  as  being  level  with  the  third 
floor,  and  the  stop  ball  5*  on  the  hand  rope  is  shown  resting  against  the 
upper  side  of  the  arm  R.  Before  the  car  would  reach  the  top-floor  stop 
the  stop  ball  would  be  in  the  position  T9  and  would  be  carried  from  that 
position  upward  to  where  it  is  drawn  in  stopping  the  elevator.  On  the 
downward  trip  the  arm  R  strikes  the  stop  ball  S'  when  it  is  in  the  posi- 
tion shown,  and  carries  it  down  to  line  S",  to  stop  the  car,  and  then  the 
floor  of  the  latter  is  even  with  the  first  floor  of  the  building.  If  the 
length  of  the  lever  L  is  proportioned  to  the  speed  of  the  car  so  as  to  give 
the  proper  amount  of  hand-rope  travel,  the  car  speed  will  be  cut  down 
gradually  until  the  car  comes  to  a  stop  even  with  the  floors  of  the  build- 
ing, without  producing  any  noticeable  shock.  If,  however,  the  hand- 
rope  movement  is  too  short  for  the  car  speed,  the  stop  on  the  down  trip 
will  be  very  violent  and  on  the  up  trip  the  car  will  not  stop  promptly, 
but  will  continue  upward  and  lift  the  valve  far  enough,  in  an  extreme 
case,  to  let  water  escape  from  the  cylinder ;  as  soon  as  the  headway  dies 
out,  the  car  will  drop  back  until  the  plunger  strikes  the  water  in  the  cyl- 
inder, when  its  backward  movement  will  be  stopped  with  a  severe  jolt. 
Even  if  the  car  does  not  run  far  enough  above  the  floor  to  open  the 
valve  in  the  reverse  direction,  if  it  should  pass  above  the  floor  any  dis- 
tance, the  plunger  will  be  drawn  away  from  the  water  in  the  cylinder 
and  on  the  return  will  be  stopped  suddenly  when  it  strikes  the  water 
again.  If  the  rope  movement  is  made  longer  than  necessary  there  will  be 
no  undesirable  effect  except  that  the  time  consumed  in  stopping  will  be 
unnecessarily  increased. 

ADJUSTMENT    OF   VALVE    MOVEMENT. 

When  the  elevator  runs  at  a  high  velocity,  it  is  generally  necessary 
to  provide  means  for  adjusting  the  movement  of  the  valve  when  it  is 
opened,  so  that  there  may  be  no  danger  of  imparting  too  high  a  speed 
to  the  car  if  the  load  is  very  light.  With  slow-running  cars  it  is  not 
necessary  to  provide  such  adjustment,  because  even  if  the  car  should  run 
50  per  cent,  faster  with  a  light  load  there  would  be  no  objection,  but  if 
the  normal  car  speed  is,  say,  400  feet  per  minute,  and  it  should  run  600 
feet  with  a  light  load,  some  damage  might  be  done,  either  when  the  car 
is  stopped  at  intermediate  floors,  or  when  it  is  stopped  automatically  at 
the  top  floor.  The  means  employed  to  adjust  the  running  speed  consist 
of  stops,  placed  on  the  hand  rope,  as  shown  at  F  F',  and  a  stationary 
stop  G,  Fig.  216.  The  stop  F  controls  the  opening  of  the  valve  for  the 
up  trip,  and  F'  controls  the  opening  of  the  valve  for  the  down  trips.  If 
these  stops  are  set  close  to  the  stationary  stop  G,  the  movement  of  the 


MAIN  AND  PILOT  CONTROL  VALVES 


261 


hand  rope  is  limited,  and  as  a  result  the  opening  of  the  valve  is  reduced. 
Contrariwise,  setting  these  stops  farther  away  from  G  increases  the 
opening  of  the  main  valve,  and,  therefore,  the  car  speed,  with  light  loads. 
There  is  no  great  danger  of  the  speed  being  too  great  with  full  load,  as 
elevators  are  not  often  so  generously  proportioned  as  regards  the  driv- 
ing power  as  to  be  able  to  run  away  when  fully  loaded,  but  when  the 
car  is  empty  the  driving  power  is  sufficient  to  develop  a  speed  much 


FIG.  217 

higher  than  the  normal.  This  is  more  likely  to  be  the  case  with  the 
cable  hydraulic  type  than  with  plunger  elevators,  because  with  the  latter 
the  weight  that  has  to  be  lifted  when  there  is  no  load  in  the  car  is  much 
greater  than  with  the  former. 

CONSTRUCTION    OF    OPERATING   VALVE. 

The  construction  of  the  operating  valve  shown  in  Fig.  216  is  illus- 
trated in  Fig.  217,  which  is  a  vertical  section  through  the  center  of  the 
valve  and  its  cylinder.  The  supply  water  enters  through  the  upper  inlet 
and  if  lever  L  is  depressed,  it  will  pass  by  piston  B  and,  following  the 
path  indicated  by  the  arrow,  will  flow  into  the  pipe  that  connects  with  the 
top  of  the  plunger  cylinder,  marked  B  in  Fig.  216.  If  lever  L  is  raised, 
the  water  can  flow  out  from  the  cylinder  and  past  piston  C  to  the  dis- 
charge tank.  The  piston  A  serves  to  balance  the  valve  and  also  to 
prevent  the  pressure  water  from  escaping  through  the  top  of  the  valve 
cylinder. 


262  HYDRAULIC  ELEVATORS 

The  valve  cylinder  is  made  of  cast  iron  and  is  provided  with  a  brass 
lining  within  which  the  valve  pistons  slide,  all  of  which  is  clearly  shown 
in  the  drawing.  The  valve  pistons  are  provided  with  leather-cup  pack- 
ings and  heads  to  retain  these  in  position.  These  heads  are  made  with 
outer  flanges  cut  away  in  a  wide  V-shape,  as  shown  at  B' ',  so  that  when 
the  valve  is  moved  to  close  the  port,  the  flow  of  water  is  stopped  grad- 
ually. For  high-speed  elevators  these  V-shaped  flanges  are  made  so  as 
to  stop  off  the  flow  of  water  quicker  than  is  necessary,  and  when  the 
elevator  is  installed  in  the  building  they  are  adjusted  by  actual  trial,  the 
edges  being  filed  off  until  the  proper  degree  of  smoothness  in  stopping 
is  obtained.  For  very  slow-running  elevators  it  is  not  necessary  to  go 
to  all  this  trouble,  as  the  shape  of  the  flanges  can  be  made  near  enough  to 
accuracy  at  the  shop. 

The  brass  lining  of  the  valve  cylinder  is  provided  with  numerous 
narrow  ports  opposite  the  outlet  so  as  to  hold  the  cup  packings  of  the 
pistons  B  and  C  in  place.  Similar  ports  are  provided  opposite  the  inlet, 
but  these  are  necessary  only  to  permit  easy  removal  of  the  valve  when 
desired,  and  also  to  make  the  whole  lining  in  one  piece.  So  far  as  the 
operation  of  the  valve  is  concerned  the  lining  could  be  made  in  two 
parts  separated  from  each  other  opposite  the  inlet  as  much  as  might 
be  necessary  to  permit  the  water  to  flow  in.  The  arm  E  that  carries 
lever  L  is  made  like  the  arm  of  the  automatic  stop  valves  described  in 
connection  with  the  passenger  plunger  elevator;  that  is,  it  is  clamped  to 
the  upper  end  of  the  valve  cylinder  above  the  point  D,  this  portion  being 
turned  to  fit  the  bore  of  the  arm  E  and  its  cap. 


CHAPTER  XXXVII 

iRACK-AND-PINION  VALVES  FOR  OTIS  FREIGHT  ELEVA- 
TORS; TYPE  OF  VALVE  USED  FOR  HIGH  SPEED; 
NOTES  ON  THE  CARE  OF  THE  PLUNGER 
AND  ROPES 

The  rack-and-pinion  valve,  which  is  used  for  elevators  that  run  at  a 
velocity  too  great  for  the  lever  valve,  is  shown  in  Fig.  218.  The  valve 
itself  is  the  same  as  the  lever  valve,  but  the  connecting  rod  F'  is  replaced 
by  the  rack  R,  and  this  meshes  with  a  pinion  P  that  is  mounted  on  the 
shaft  that  carries  the  hand  sheave  5\  The  rack  R  is  made  of  a  round  rod 
with  the  teeth  cut  on  one  side.  A  casing  D  is  provided  to  cover  the  rack 
and  pinion,  and  this  is  clamped  against  the  upper  end  of  the  valve  cylinder 
by  means  of  the  cap  D'.  Opposite  the  pinion  P  the  cover  D  has  a  fin- 
ished surface  against  which  the  rack  bears  so  as  to  be  held  in  mesh 
with  the  pinion.  This  sliding  surface  and  the  pinion  shaft  are  provided 
with  grease  cups  E  and  F  to  keep  them  properly  lubricated.  The  rack 
is  so  formed  at  the  ends  that  it  cannot  be  run  out  of  gear,  even  if  there 
are  no  stops  outside  of  the  valve  to  limit  the  movement  of  the  hand  rope. 
When  the  pinion  reaches  the  last  tooth  it  strikes  the  curved  end  of  the 
rack  and  can  go  no  farther. 

TYPE  OF  VALVE  USED  FOR  HIGH  SPEED. 

The  type  of  valve  used  when  the  car  speed  is  so  great  that  the  plain 
rack-and-pinion  valve  will  not  give  sufficient  hand-rope  movement,  is 
shown  in  Fig.  219,  which  presents  a  vertical  elevation  in  section  and  also 
a  plan.  The  hand-rope  sheave  S  is  mounted  on  a  shaft  A  that  carries 
a  pinion  B,  which  meshes  with  a  gear  wheel  C  mounted  on  a  second 
shaft  D.  This  shaft  carries  a  second  pinion  E  that  meshes  with  the  rack 
F  on  the  end  of  the  valve  rod.  The  relative  positions  of  these  parts  is 
more  fully  shown  in  the  plan  view  of  the  valve,  at  the  top  of  the  drawing. 
The  pinion  B  and  gear  C  are  covered  with  a  casing,  and  so  are  the  rack 
F  and  pinion  E.  The  rack  F  is  provided  with  stops  on  the  back  at  each 
end  so  that  it  carihot  be  run  out  of  gear  with  the  pinion. 

All  the  valves  shown  in  the  preceding  illustrations  are  balanced  insofar 
as  the  pressure  of  the  supply  water  is  concerned,  as  this  pushes  up  against 
the  piston  A  and  down  against  the  piston  B,  and  as  both  pistons  are  of 

263 


264 


HYDRAULIC  ELEVATORS 


the  same  diameter,  the  pushes  are  balanced,  but  if  the  discharge  tank  is 
higher  than  the  valve,  as  is  generally  the  case,  the  valve  will  not  be  in 
balance  because  there  will  be  a  pressure  acting  under  the  piston  C  that 
will  be  greater  than  the  atmospheric  pressure  acting  on  the  top  of  the 
piston  A.  For  cases  of  this  kind  it  is  necessary  to  provide  another  valve 
piston  under  C  so  that  the  back  pressure  from  the  discharge  tank  may 
act  upon  it  and  thus  balance  the  pressure  acting  under  the  piston  C. 
The  type  of  valve  used  for  such  installations  is  shown  in  Fig.  220.  The 
only  difference  between  this  and  the  other  valves  is  that  a  section  is  added 


FIG.  318 

to  the  lower  end  of  the  valve  cylinder  and  the  valve  rod  is  lengthened 
out  so  as  to  carry  an  additional  valve  piston  D.  With  this  construction 
the  two  pistons  C  and  D  balance  the  back  pressure  from  the  discharge 
tank,  and  the  pistons  A  and  B  balance  the  pressure  from  the  supply  pipe. 

PROPER  CARE  OF  THE  ROPES. 

Plunger  elevators  have  fewer  moving  parts  than  cable  hydraulic 
machines,  hence  they  should  be  easier  to  keep  in  proper  running  order. 
The  counterbalance  ropes  run  over  a  sheave  located  at  the  top  of  the 
elevator  well  in  the  same  position  as  the  main  overhead  sheave  of  cable- 


RACK-AND-PINION  VALVES 


hoisted  elevators.  This  sheave  is  of  the  same  type  as  those  used  with 
cable  elevators  and  is  mounted  in  the  same  way,  so  that,  it  requires  the 
same  attention.  The  ropes  that  run  over  it  do  not  require  as  close  inspec- 
tion as  the  lifting  ropes  of  cable  machines  because  they  are  several  times 
as  large  as  is  necessary  to  support  the  weight  of  the  counterbalance, 
owing  to  the  fact  that  they  not  only  hold  this  weight,  but  also  act  as  a 


FIG.  219 


FIG.    220 


compensating  balance  to  offset  the  varying  weight  of  the  column  of  water 
displaced  by  the  plunger.  The  diameter  of  the  plunger  is  almost  invari- 
ably 6l/2  inches,  so  that  the  water  displaced  for  each  foot  of  length  is 
0.2304  cubic  foot,  and  the  weight  of  this  quantity  of  water  is  about  14.33 
pounds.  The  weight  of  the  ropes  required  to  compensate  for  the  varying 
weight  of  the  water  displaced  by  the  plunger  is  just  one-half  this  amount, 
as  can  be  easily  seen  from  the  fact  that  each  foot  of  rope  hanging  above 
the  car  adds  its  weight  to  the  latter,  while  each  foot  of  rope  hanging 
above  the  counterbalance  deducts  its  weight  from  that  of  the  car ;  hence, 


266  HYDRAULIC  ELEVATORS 

to  exactly  balance  the  water  displaced  by  the  plunger  the  ropes  must 
weigh  one-half  as  much  per  running  foot. 

Although  the  ropes  are  far  stronger  than  necessary,  it  is  important 
to  keep  them  all  drawn  up  to  the  same  tension,  and  this  can  be  done  with 
a  sufficient  degree  of  accuracy  by  pushing  them  sidewise  at  a  point  sev- 
eral feet  from  the  end  and  noting  whether  they  all  offer  about  the  same 
resistance  to  being  moved.  The  end-fastening  bolts  must  be  held  so 
that  they  may  not  work  loose  and  slack  the  ropes.  As  a  rule  these  bolts 
are  provided  with  means  for  holding  the  nuts  from  turning,  but  even 
these  locking  devices  can  get  out  of  order  occasionally,  and  they  should 
be  inspected  frequently. 

The  ropes  that  operate  the  valves  should  be  kept  in  perfect  condition, 
and  the  sheaves  over  which  they  run  should  have  the  bearings  well  lubri- 
cated; care  should  be  taken  that  there  is  nothing  nearby  that  can  fall 
into  them  and  cause  the  ropes  to  run  off,  or  to  be  jammed.  This  applies 
especially  to  the  automatic-stop  valve  ropes,  for  if  these  should  become 
disabled  the  car  would  in  all  probability  run  far  enough  above  the  upper 
floor  to  do  damage,  or  strike  the  lower  bumpers  violently  the  first  time 
the  operator  permitted  the  car  to  run  to  the  end  of  the  trip  without  closing 
the  main  valve. 

PLUNGER    WILL    GIVE   LITTLE   TROUBLE. 

The  plunger,  if  kept  in  proper  condition,  will  give  very  little  trouble, 
but  if  an  elevator  is  out  of  service  for  some  time  and  the  plunger  becomes 
rusty  from  want  of  proper  protection,  when  it  is  started  up  the  rough 
surface  will  act  upon  the  packing  like  sandpaper,  and  soon  cause  it  to 
leak.  Whenever  an  elevator  is  put  out  of  commission  for  any  length  of 
time,  which  is  unusual,  the  plunger  should  be  run  slowly  on  the  last 
downward  trip  that  it  makes,  and  the  surface  should  be  wiped  dry  and 
then  covered  with  a  hard  lubricating  grease,  so  that  in  passing  down 
through  the  stuffing  box  into  the  cylinder,  all  the  grease  will  not  be 
rubbed  off,  but  a  thin  layer  will  be  left  that  will  serve  to  protect  the 
metal.  If  the  elevator  plunger  is  lubricated  by  a  lubricating  compound 
put  in  the  water,  it  will  not  be  necessary  to  grease  the  plunger,  as  it  will 
receive  a  protective  coating  from  the  greasy  water. 

When  an  elevator  that  has  been  idle  for  some  time  is  started  up,  the 
plunger  should  be  carefully  examined,  and  if  it  shows  any  rough  spots 
they  should  be  smoothed  off,  but  emery  should  not  be  used  for  this  pur- 
pose. As  a  rule  use  the  softest  polishing  material  that  will  do  the  work, 
such  as  whiting,  pumice  stone,  and  in  extreme  cases  sandpaper.  Draw- 
filing  with  a  very  fine  file  is  the  best  means  for  smoothing  the  rough  spots 
if  they  are  very  rough,  but  be  sure  the  file  is  a  dead  smooth  cut  or  next 
to  it.  After  draw-filing  a  fine  polish  can  be  obtained  by  using  the  finest 


RACK-AND-PlNION    VALVES 


267 


grade  of  sandpaper  and  finishing  with  rouge  cloth.    In  fact,  for  ordinary 
roughness,  the  rouge  cloth  alone  will  answer  every  purpose. 

TO   RENEW    PLUNGER    PACKING. 

Whenever  it  becomes  necessary  to  renew  the  plunger  packing,  the  first 
thing  to  do  is  to  run  the  car  downward  until  it  rests  solidly  upon  the 
bumpers.  Then  the  hand  valve  in  the  supply  tank  should  be  closed,  so 
that  water  cannot  flow  in  from  the  pressure  tank.  If  the  discharge  tank 
is  higher  than  the  bottom  of  the  valve,  which  is  generally  the  case,  there 
will  be  a  hand  valve  in  the  discharge,  and  this  must  also  be  closed  so  that 
water  cannot  flow  back  from  the  discharge  tank.  If  any  part  of  the  pipe 
connections  between  the  two  hand  valves  just  mentioned  is  higher  than  the 
top  of  the  cylinder,  there  will  be  drain  cocks  through  which  the  water 


Note: 


A-  Actual  Plunger  Dia.-f  %!J 
FIG.    221 


FIG.    222 


may  be  drawn  ofT,  so  that  when  the  stuffing-box  gland  is  removed  water 
may  not  escape  and  flood  the  floor.  The  way  in  which  the  stuffing  box 
of  the  Otis  plunger  is  repacked  can  be  understood  by  the  aid  of  the  detail 
drawings  of  the  box  and  packing  presented  in  Figs.  221  to  224.  Fig.  221 
is  a  vertical  section  through  the  several  parts  of  the  structure.  The  stuf- 
fing is  shown  at  A  and  the  compressing  gland  is  marked  B.  Between  the 
gland  B  and  a  ring  C  are  two  rings  of  babbitt  metal  which  are  provided 
to  rub  the  oil  off  the  plunger  as  it  ascends  and  thus  prevents  it  from 
overflowing  when  the  plunger  comes  down.  As  an  extra  precaution, 
however,  the  basin  D  is  provided  to  catch  any  drippings  of  oil. 

The  packing  A  can  be  any  of  the  soft  kinds  suitable  for  steam-engine 
stuffing  boxes,  but  the  Otis  company  makes  a  special  ring  packing  in  two 


268 


HYDRAULIC  ELEVATORS 


parts,  one  of  leather  and  the  other  of  rubber,  and  this  lasts  longer  and 
remains  tight  until  worn  out.  A  sectional  drawing  of  this  packing  is 
given  in  Fig.  222.  In  this  illustration  P  represents  a  portion  of  the  side 
of  the  plunger,  B  is  the  lower  end  of  the  stuffing-box  gland,  B'  is  a  por- 
tion of  the  stuffing-box  casting  and  A  A'  are  the  two  parts  of  the  packing 
rings;  the  ring  A  is  made  of  leather  and  A'  is  made  of  rubber.  These 
two  parts  are  made  so  as  to  just  fill  the  stuffing-box  chamber  when  the 
gland  B  is  screwed  down  to  the  lowest  position,  hence  the  packing  is 
held  securely  in  place  but  not  compressed.  Two  rings  are  used  because  it 
is  necessary  to  cut  them  on  one  side  to  put  them  in  place  without  lifting 
the  plunger  out  of  the  cylinder,  and  by  using  two  rings  and  "staggering" 


FG.  223 


FIG.  224 


the  cuts,  a  tight  joint  can  be  made.  The  two  rings  are  made  to  fit  each 
other;  the  pressure  of  the  water  acts  against  the  inner  sides  of  A'  and 
forces  the  outside  part  against  the  stuffing-box  casting,  making  a  tight 
joint  at  this  point,  and  the  inside  part  is  forced  against  ring  A,  making  a 
tight  joint  between  the  two  rings,  at  the  same  time  forcing  A  against 
the  plunger  to  make  a  tight  joint  at  this  point. 

THE  STUFFING-BOX  CASTING. 

The  construction  of  the  stuffing-box  casting  is  clearly  shown  in  Fig. 
221  and  the  construction  of  the  gland  B  is  more  fully  illustrated  in  Fig. 
223,  which  shows  a  sectional  elevation.  This  view  shows  that  between 
the  top  and  bottom  edges  of  the  casting  there  is  an  annular  recess  which 
forms  an  oil  well  that  surrounds  the  plunger  and  keeps  the  surface  of  the 


RACK-AND-PINION  VALVES  269 

latter  well  lubricated.  Oil  flows  into  this  recess  from  the  oil  cup  shown 
in  Fig.  221.  At  the  upper  end  of  the  gland  there  is  another  recess  which 
contains  the  babbitt  ring  scrapers  that  wipe  the  oil  off  the  plunger  as  it 
rises.  To  hold  these  in  place  the  ring  C  shown  in  Fig.  221  is  provided, 
and  this  is  held  in  position  by  the  studs  E,  that  hold  down  the  gland 
B.  The  babbitt  rings  are  of  square  cross  section,  as  shown  in  Fig.  224, 
and  are  divided  into  halves,  the  ends  being  cut  on  an  angle  as  shown  at 
A.  On  the  outer  surface  of  the  ring  is  cut  a  groove  that  is  large  enough 
to  accommodate  a  brass-wire  spring,  which  presses  the  two  halves  of  the 
ring  against  the  plunger  surface.  Two  of  these  rings  are  used,  as  shown 
in  Fig.  221,  and  they  are  set  so  as  to  break  joints. 

To  determine  whether  the  plunger  stuffing  box  needs  repacking  is  a 
very  simple  matter.  If  it  leaks  it  must  be  repacked,  unless  it  is  filled  with 
an  ordinary  packing  in  which  case  it  may  possibly  be  made  tight  by  screw- 
ing down  the  gland  B.  As  the  top  of  the  cylinder  is  in  sight,  water  run- 
ning out  of  the  stuffing  box  can  easily  be  seen.  If  it  is  not  known 
whether  the  packing  is  of  the  type  shown  in  Fig.  222  or  not,  this  can  easily 
be  determined  by  feeling  around  the  outside  of  the  upper  flange  of  the 
gland  B  to  ascertain  whether  it  is  resting  against  the  lower  casting  or 
not.  If  it  is  not  down  tight,  the  packing  is  probably  hemp,  and  a  few 
turns  of  the  studs  may  be  sufficient  to  prevent  the  escape  of  water.  If 
gland  is  down  against  the  lower  casting,  the  packing  may  be  rings  that 
are  worn  out,  or  hemp  that  is  compressed  as  far  as  the  gland  will  force 
it.  If  it  becomes  necessary  to  renew  the  packing  and  there  are  no  packing 
rings  at  hand,  use  hemp  well  greased,  and  if  this  works  well  keep  on 
using  it.  It  is  by  no  means  certain  that  the  rings  will  work  better  than 
hemp,  although  they  are  considered  to  be  able  to  stand  up  better  against 
the  wear  of  high-speed  plungers. 

If  a  plunger  elevator  settles  when  standing  at  a  landing  above  the  first 
floor,  and  no  water  escapes  from  the  plunger  stuffing  box,  the  valves  leak, 
that  is,  providing  the  valve  is  properly  closed.  To  renew  the  packing 
it  is  necessary  to  remove  the  valve  from  the  casing,  and  before  this  is 
done  the  hand  valves  in  the  supply  and  discharge  pipes  must  be  closed 
and  the  water  drawn  from  the  valve  casings.  The  car  must  be  run  down 
so  as  to  rest  on  the  bumpers  at  the  lower  floor  before  this  work  is  begun. 
The  hand-rope  valves  used  with  freight  elevators  are  best  removed 
through  the  upper  end,  although  it  is  also  possible  to  remove  them  from 
the  lower  end,  providing  there  is  space  between  the  bottom  of  the  valve 
cylinder  and  the  floor  for  their  removal.  This  way  of  taking  out  the 
valves  is  not  advisable,  however,  because  it  involves  disconnecting  the 
discharge  pipe,  which  is  considerable  work;  nevertheless,  there  may  be 
cases  where  the  location  of  the  valves  renders  this  method  necessary. 


270 


HYDRAULIC  ELEVATORS 


When  the  valve  is  removed  through  the  upper  end,  if  it  is  of  the 
lever  type,  the  pivot  pin  around  which  the  lever  swings  is  taken  out  so 
that  the  lever  may  be  removed,  and  then  the  valve  can  be  lifted  out  of  the 
cylinder.  If  the  valve  is  of  the  rack-and-pinion  type,  the  casing  that 
covers  the  rack  is  removed  together  with  the  pinion  and  shaft,  and  then 
the  valve  can  be  drawn  out.  If  the  valve  is  of  the  double-gear  rack- 
and-pinion  type  it  is  only  necessary  to  remove  the  shaft  that  holds  the 
pinion  that  meshes  with  the  rack,  and  also  the  covering  of  the  latter ;  with 
these  parts  removed,  the  valve  can  be  drawn  out.  If  the  brass  lining  of 
the  valve  cylinder  happens  to  be  in  two  parts  there  may  be  some  difficulty 
experienced  in  passing  the  cups  of  the  lower  valve  pistons  up  into  the 
upper  lining,  but  if  this  occurs  the  valve  should  be  lowered  so  as  to 
smooth  up  the  cups,  and  then  tried  again  with  more  care.  There  is  very 
little  liability  of  having  trouble  in  this  direction,  because  the  lower  end  of 
the  top  cylinder  lining  is  made  with  the  inner  corner  well  rounded  off 
and  the  top  end  of  the  lower  lining  is  made  in  the  same  way.  There  is 
no  difficulty  in  getting  the  valve  back  into  the  cylinder,  because  the  cup 
packings  are  not  forced  in  edge  first,  or  against  the  grain,  as  it  might  be 
expressed. 

REMOVAL   OF   THE   VALVES. 

The  main  valve  of  passenger  elevators  is  removed  from  the  back  end, 
as  it  cannot  be  removed  from  the  front  end,  owing  to  the  fact  that  the 
rear  piston  is  larger  than  the  others.  In  the  valve  Fig.  208,  the  upper 
valve  pistons  can  be  removed  from  either  end,  as  all  the  pistons  are  of  the 
same  size ;  but  it  is  less  trouble  to  remove  them  from  the  back  end,  as 
then  it  is  not  necessary  to  disturb  any  of  the  connecting  levers. 

When  new  leather  cups  are  to  be  put  in  the  valves  they  should  be 
obtained  from  the  makers,  so  that  they  may  be  of  the  proper  depth.  In 
some  cases  it  matters  little  what  the  depth  of  the  cup  is,  so  long  as  it 
makes  a  tight  joint;  this  is  the  case  with  the  pistons  in  the  lower  cylinder 
of  the  valve,  Fig.  208,  because  the  packings  have  only  to  maintain  a  tight 
joint.  There  are  cases,  however,  in  which  the  edge  of  the  cup  forms  the 
edge  of  the  valve,  and  when  it  passes  over  a  port,  closes  it  and  stops  the 
flow  of  water.  To  make  the  elevator  work  well  it  is  necessary  for  such 
valves  to  have  a  certain  amount  of  lap,  and  therefore  the  cup  packing 
should  be  of  the  proper  proportion.  In  the  several  valves  of  the  Otis 
plunger  elevators,  for  example,  it  will  be  noticed  that  in  the  valve  piston 
which  shuts  off  the  flow  of  water  from  the  supply  pipe  into  the  cylinder 
the  cup  is  turned  toward  the  supply  pipe,  hence  its  edge  forms  the 
edge  of  the  valve  and  its  length  determines  the  amount  of  lap,  so  that 
if  the  cup  is  too  deep  there  will  be  too  much  lap  and  if  it  is  too  shallow 
there  will  not  be  enough  lap. 


RACK-AND-PINION  VALVES  271 

Of  the  two  evils,  too  much  lap  is  the  lesser,  so  that  if  for  any  reason 
a  cup  is  used  that  is  not  of  the  proper  shape,  take  one  that  is  deeper  than 
it  should  be.  If  the  lap  is  reduced  the  liability  of  reversing  the  elevator 
whenever  it  is  stopped  is  increased,  because  a  slight  movement  beyond 
the  point  where  the  valves  are  closed  will  open  them  for  the  reverse 
direction  of  movement.  These  observations  relative  to  the  proportions 
of  cup  packings  apply  to  simple  hand-rope  valves  as  well  as  to  the  pilot- 
valve  type. 

The  pilot  valve  and  the  V  valve  can  be  removed  from  either  end  when 
it  becomes  necessary  to  renew  the  packings,  but  generally  it  will  be  found 
easier  to  draw  the  pilot  out  through  the  back  end  and  the  other  valve 
through  the  front.  In  replacing  the  valves  they  can  best  be  put  in  through 
the  back.  If  any  trouble  is  experienced  in  getting  the  front  cup  of  the 
pilot  valve  past  the  two  port  openings,  the  trouble  can  be  avoided  by 
putting  the  valve  in  from  the  back  with  the  two  rear  cups  in  place,  and 
then  the  front  cup  can  be  put  on  from  the  front  end.  In  doing  this,  care 
must  be  taken  that  the  end  fork  which  holds  the  connecting-rod  end  is 
screwed  upon  the  valve  rod  tight,  so  as  to  force  the  packings  firmly  into 
position.  The  safest  course  is  to  note  the  position  of  the  end  of  the  valve 
rod  in  the  fork  before  taking  it  apart,  and  to  screw  it  up  to  that  same 
position  when  putting  it  back.  This  plan  should  also  be  followed  with  the 
nuts  at  the  back  end. 

Referring  to  the  drawings  of  the  Otis  plunger-elevator  pilot  valves, 
as  well  as  the  main  valves,  it  will  be  found  that  no  means  are  provided 
for  adjusting  the  position  of  the  cup  packings  lengthwise  of  the  piston 
rod ;  such  adjustment  is  not  provided  because  it  is  not  required.  When 
the  valves  are  made  the  various  parts  are  made  of  the  proper  length  to 
bring  all  the  cups  in  the  proper  positions,  and  the  only  way  in  which  the 
adjustment  can  be  made  wrong  is  by  using  cups  that  are  not  of  the 
proper  length  when  replacing  those  that  are  worn  out. 

AUTOMATIC-STOP    VALVES. 

The  automatic-stop  valves  of  the  Otis  plunger  elevators  are  very  simi- 
lar to  the  main  valves  used  with  hand-rope  control,  and  are  taken  out 
of  the  valve  cylinder  through  the  upper  end  in  the  same  way  as  the  latter. 
These  valves  have  the  cup  packings  set  in  the  right  position  when  first 
installed  and  have  no  means  for  adjusting  their  position  because  such 
adjustment  is  not  necessary.  In  repacking  them  all  that  is  necessary  is 
to  use  cups  of  the  same  shape  as  the  original  cups.  All  that  has  been 
said  in  relation  to  the  main  valves  applies  equally  well  to  the  automatic- 
stop  valves. 


CHAPTER  XXXVIII 

REPLACING  WORN  SHOES;  HOW  TO  DISCONNECT  THE 
PLUNGER;  CARE  OBSERVED  IN  HANDLING  PARTS 

The  only  point  that  remains  to  be  considered  in  connection  with  the 
Otis  plunger  elevator  is  the  lower  end  of  the  plunger.  As  the  cylinder 
is  from  2  to  3  inches  larger  in  diameter  than  the  plunger,  the  lower  end 
of  the  latter  has  to  be  guided  so  that  it  may  not  wobble  around  when 
the  elevator  is  in  motion.  The  guides  used  for  this  purpose  are  shoes 
made  of  hard  brass,  their  shape  being  shown  in  Fig.  225.  In  some  cases 
three  shoes  are  used,  as  shown  in  this  drawing,  the  shoes  being  spaced 
equally  around  the  circle.  The  lower  part  of  Fig.  225  is  a  horizontal  sec- 
tion through  the  lower  end  of  the  plunger,  showing  the  position  of  the 
three  shoes  S,  as  well  as  the  sides  T,  of  the  slots  within  which  they  move. 
In  some  plungers  four  shoes  are  provided,  as  shown  in  Fig.  226.  In  both 
arrangements  the  shoes  are  pivoted  at  the  upper  ends  and  are  held  from 
swinging  out  too  far  by  a  stop  ring  at  the  lower  end,  as  shown  in  both 
drawings.  The  cylinder  itself  prevents  the  shoes  from  spreading  out 
beyond  a  certain  point,  but  if  the  retaining  ring  were  not  provided  at  the 
lower  end  the  plunger  would  not  be  held  central  unless  all  the  springs  A 
were  of  equal  tension. 

As  the  shoes  slide  against  the  wall  of  the  cylinder  they  wear  out  and 
from  time  to  time  have  to  be  replaced.  The  rapidity  with  which  they  wear 
out  depends  on  several  things,  such  as  the  character  of  the  cylinder  sur- 
face, the  straightness  of  the  cylinder,  the  hardness  of  the  metal,  etc.  In 
the  early  days  of  plunger  elevators  the  lengths  of  pipe  that  form  the 
cylinder  were  put  together  in  the  same  way  as  a  line  of  piping  so  that  the 
joints  presented  the  appearance  illustrated  in  Fig.  227,  which  represents 
a  section  through  one  side  of  the  cylinder  at  a  joint.  With  a  joint  of  this 
type  the  shoes  will  wear  out  rapidly,  as  the  edges  a  a  cut  them  away. 
This,  however,  is  not  the  only  objection  to  such  cheap  construction,  for 
the  constant  passing  of  the  shoes  across  the  joints  results  in  wearing 
away  the  edges  a  a,  so  that  in  time  the  cylinder  is  enlarged  at  this  point, 
with  the  result  that  when  the  plunger  end  passes  it  it  swings  from  side 
to  side.  All  plunger  cylinders  are  put  together  now  with  great  care,  the 
ends  of  the  pipes  being  turned  true  in  a  lathe  and  screwed  into  the  coupling 
sleeves  until  the  ends  come  together  as  is  shown  in  Fig.  228.  Even  with 

272 


REPLACING  WORN  SHOES 


273 


this  construction,  however,  there  is  a  possibility  of  having  uneven  sur- 
faces at  the  joints,  because  the  thread  may  not  be  central  with  the  pipe, 
in  which  case  the  metal  will  be  thicker  on  one  side  than  the  other,  and 


I 


FIG.  225  FIG.  226 

if  the  thin  part  of  one  pipe  comes  opposite  the  thick  part  of  the  other,  the 
result  will  be  as  shown  in  Fig.  229,  and  thus  a  cutting  edge  will  be 
formed  that  will  cause  the  shoe  to  wear  away  faster  than  if  it  rubbed 


274 


HYDRAULIC  ELEVATORS 


against  a  smooth  surface.  The  life  of  these  shoes  is  therefore  very  vari- 
able, and  according  to  the  opinion  of  those  who  have  had  the  greatest 
experience  with  plunger  elevators  may  range  all  the  way  from  five  or 
six  years  down  to  as  many  months. 

REPLACING  WORN  SHOES. 

When  the  shoes  wear  out  to  such  an  extent  that  they  do  not  all  touch 
the  sides  of  the  cylinder  at  the  same  time  they  must  be  replaced,  and  it  is 
needless  to  say  that  to  replace  them  it  is  necessary  to  draw  the  end  of  the 
plunger  out  of  the  cylinder.  There  are  two  ways  in  which  the  end  of 


FIG.  227      FIG.  228         FIG.  229 


the  plunger  may  be  drawn  out  of  the  cylinder ;  one  is  by  lifting  the  car 
and  plunger  high  enough  to  raise  the  lower  end  of  the  plunger  above  the 
top  of  the  cylinder.  This  can  be  done  in  some  cases  where  the  overhead 
beams  are  high  enough,  but  in  most  buildings  if  the  car  is  raised  as  far 
as  it  can  be  the  end  of  the  plunger  will  still  be  within  the  cylinder.  In 
such  case  the  only  way  to  get  the  end  out  is  by  disconnecting  the  plunger 
at  one  of  the  joints  and  then  lifting  the  lower  portion. 

The  first  thing  to  do  in  either  case  is  to  run  the  car  up  as  far  as  the 
pressure  of  the  water  will  carry  it.  If  the  plunger  can  be  lifted  out 
whole,  the  car  is  made  fast  to  the  overhead  beams  by  means  of  strong 
ropes  that  are  abundantly  able  to  hold  the  load.  Next  a  powerful  dif- 
ferential chain  block  is  put  in  position  to  lift  the  car,  being  secured  to  the 
overhead  framing  and  to  the  top  car  frame.  The  water  is  then  shut  off 
from  the  cylinder  by  closing  the  hand  valves  in  the  supply  and  discharge 


REPLACING  WORN  SHOES  275 

pipes,  and  the  water  in  the  valves  and  piping  is  drained  if  these  are  above 
the  top  of  the  cylinder,  but  not  otherwise.  Having  done  this,  the  stuffing- 
box  casting  is  unscrewed  from  the  top  of  the  cylinder  casting,  and  is  made 
fast  to  the  plunger  so  that  it  will  not  slide  down  when  the  plunger  is 
raised.  All  this  being  done,  the  car  and  plunger  are  raised  until  the  end 
of  the  latter  comes  out  of  the  cylinder.  As  the  car  is  raised,  the  slack  in 
the  ropes  that  hold  it  to  the  overhead  beams  is  taken  up  so  that  if  the 
hoisting  tackle  should  break,  the  car  would  drop  only  a  few  inches. 

When  the  end  of  the  plunger  is  raised  above  the  cylinder,  if  it  is  found 
that  all  the  shoes  are  not  badly  worn  they  need  not  all  be  replaced,  but  as 
their  cost  is  not  great,  and  the  trouble  of  replacing  them  is  considerable, 
it  is  wise  to  not  be  too  economical ;  hence,  unless  the  wear  is  only  trivial, 
they  should  be  discarded.  After  the  new  shoes  are  put  in  place  and  the 
pins  and  springs  set  securely  in  position  so  that  they  cannot  work  out,  the 
plunger  is  lowered  into  the  cylinder  until  the  stuffing-box  casting  rests  on 
the  top  of  the  cylinder  casting.  Then  the  bolts  are  put  in  and  screwed  up 
so  as  to  make  a  tight  joint.  The  next  thing  to  do  is  to  remove  entirely 
the  ropes  that  hold  the  car  to  the  overhead  beams  and  lower  the  chain 
tackle  until  it  slacks  up,  which  shows  that  the  plunger  is  resting  on  the 
water  in  the  cylinder.  The  tackle  is  then  removed  and  the  valves  in  the 
supply  and  discharge  pipes  are  opened  and  the  elevator  is  ready  to  run. 
After  it  starts  up,  examine  the  joint  between  the  stuffing  box  and  top  of 
cylinder  to  see  if  it  is  tight ;  if  it  is  not,  tighten  the  bolts,  and  if  this  does 
not  make  it  tight,  the  car  will  have  to  be  fastened  up  to  the  overhead 
beams  again  and  the  water  turned  off  so  as  to  loosen  the  bolts,  separate 
the  joint,  clean  it  out  and  make  it  over  again,  using  more  care  than  before 
so  as  to  be  surer  of  making  a  good  job  of  it. 

TO  DISCONNECT  THE    PLUNGER. 

When  the  distance  between  the  top  of  the  car  and  the  overhead  beams 
is  not  sufficient  to  lift  the  car  high  enough  to  draw  the  lower  end  of  the 
plunger  out  of  the  cylinder,  and  it  becomes  necessary  to  disconnect  the 
plunger  at  one  of  the  joints,  the  work  is  done  as  follows :  After  the  car 
is  run  up  to  the  top  floor  and  made  fast  to  the  overhead  beams,  the  water 
is  shut  off.  The  next  step  is  to  place  wooden  clamps  on  the  plunger  above 
and  below  the  bottom  joint,  which  is  at  the  top  of  the  first  length  of  pipe. 
The  illustration,  Fig.  230,  shows  the  position  of  these  clamps,  which  must 
be  made  to  fit  the  plunger  accurately  in  order  not  to  spring  it  out  of  shape. 
The  clamps  A  are  to  be  made  long  enough  to  reach  from  one  side  of 
the  elevator  well  to  the  other,  so  that  they  may  be  firmly  secured  to  the 
car  guides,  or  some  other  suitable  support.  The  object  of  these  clamps  is 
to  hold  the  upper  part  of  the  plunger  from  turning  so  that  when  the 


276 


HYDRAULIC  ELEVATORS 


lower  joint  is  unscrewed  the  upper  ones  may  not  be  disturbed.  It  is 
necessary  that  the  clamp  A  be  so  tight  that  it  cannot  turn  when  the  pipe 
is  unscrewed.  To  make  sure  that  it  does  not  turn,  make  a  chalk  mark 
on  the  plunger  and  one  on  the  clamp  opposite  and  watch  them  when  the 
clamp  B  is  turned.  Before  starting  to  turn  the  latter  clamp,  look  at  the 


FIG.  230 

joint  and  see  if  it  is  marked  to  show  the  position  of  the  two  parts  when 
tightly  screwed  up.  If  not,  make  one  with  a  cold  chisel  that  has  a  sharp, 
straight  edge.  Then  turn  the  clamp  B  to  unscrew  the  pipe.  If  it  sticks 
at  first,  it  can  be  easily  started  by  rapping  the  clamp  rather  hard  with  a 
large  hammer  or  a  sledge  while  pulling  on  the  clamp. 

After  the  pipe  has  been  worked  off,  say  1/4  of  an  inch,  place  under 
the  clamp  B  supports  as  shown  at  C  C,  so  that  it  may  not  be  able  to  drop 


REPLACING  WORN  SHOES 


277 


when  nearly  loose  and  thereby  strip  the  last  few  threads  of  the  pipe  or 
the  coupling.  The  supports  C  C  are  here  shown  a  considerable  distance 
below  the  clamp  B,  but  they  should  be  held  against  it  to  carry  the  weight 
and  relieve  the  screw  thread  from  strain.  It  might  be  supposed  that  this 
is  not  necessary  as  the  buoyancy  o£  the  plunger,  together  with  the  fric- 


FIG.  231 

tion  of  the  stuffing,  might  be  sufficient  to  hold  the  weight;  but  it  is  not 
safe  to  depend  on  this,  because  the  water  displaced  only  weighs  about 
14  pounds  per  running  foot  of  the  plunger  while  the  lower  end  of  the 
latter,  on  account  of  the  weight  of  the  lower  casting,  will  probably  weigh 
30  pounds  per  foot.  After  the  joint  has  been  entirely  unscrewed,  the 
stuffing-box  casting  is  unscrewed  and  then  the  lower  section  of  the 


278  HYDRAULIC  ELEVATORS 

plunger  is  lifted  out  of  the  cylinder,  the  upper  portion  of  the  plunger 
being  sprung  to  one  side  to  make  room.  Unless  the  elevator  is  of  very 
low  lift,  say  less  than  100  feet,  no  damage  will  be  done  to  the  plunger  if 
it  is  sprung  over  to  the  side  of  the  well,  as  this  much  bend  is  far  within 
the  elastic  limit  of  the  metal. 

After  the  old  shoes  are  removed  the  lower  section  of  the  plunger 
is  put  back  in  the  cylinder  and  lowered  until  the  end  of  the  upper  part 
can  be  brought  into  alinement  with  it;  the  thread  is  then  covered  with 
red  lead  for  about  half  its  length  to  make  a  water-tight  joint,  and  the 
sections  are  screwed  together  a  trifle  farther  than  originally.  On  the 
last  turn,  when  the  chisel  marks  come  in  line,  the  two  parts  will  be  in 
their  original  relation,  but  the  joint  will  not  be  as  tight  as  before,  because 
every  time  a  screwed  joint  is  taken  apart  and  put  together,  the  metal 
wears  a  trifle,  leaving  room  for  slightly  more  ".take-up"  when  tightening 
it  "home." 

In  the  foregoing  methods  of  taking  out  the  lower  end  of  the  plunger, 
the  stuffing  box  is  raised  with  the  plunger.  This  is  done  because  it  would 
be  likely  to  damage  the  packing  if  the  guide  shoes  at  the  lower  end  of 
the  plunger  were  pulled  and  pushed  across  it.  The  type  of  packing  shown 
in  Fig.  222  could  stand  this  treatment,  but  hemp  packing  could  not. 

When  the  lower  end  of  the  plunger  is  disconnected,  care  must  be  taken 
not  to  allow  it  to  get  away  and  drop  into  the  cylinder.  There  is  not  a 
great  deal  of  danger  of  such  a  thing  happening,  because  if  the  clamp  B 
is  not  removed  the  plunger  end  cannot  drop.  There  is  no  reason  for 
removing  the  clamp  and  every  reason  for  keeping  it  in  place,  because  it 
is  an  excellent  point  of  attachment  for  the  tackle  used  to  pull  the  plunger 
end  out  of  the  cylinder.  Notwithstanding  all  this,  it  is  possible  for 
something  to  occur  that  would  cause  the  plunger  end  to  get  loose  and  slip 
down  into  the  cylinder,  and  the  possibility  must  be  kept  in  mind.  If  one 
should  ever  get  into  such  a  scrape,  he  could  get  out  of  it  by  using  a 
grapple  of  the  type  shown  in  Fig.  231,  which  consists  of  dogs  A  A 
mounted  on  the  end  of  a  rod  B  and  arranged  to  swing  out  so  as  to  catch 
against  the  under  side  of  the  shoulder  E  in  the  lower  end  casting  of  the 
plunger.  After  the  plunger  is  raised  out  of  the  cylinder  and  made  fast, 
the  grapple  can  be  taken  out  by  pulling  up  the  cords  d  d,  thereby  drawing 
the  ends  of  the  dogs  into  a  position  where  they  cannot  catch  against  the 
shoulder  E. 


CHAPTER  XXXIX 

THE  "STANDARD"  PLUNGER  ELEVATOR;  PRINCIPAL  DIF- 
FERENCE BETWEEN  THIS  AND  THE  OTIS  TYPES; 
VALVE  CONSTRUCTION  AND  OPERATION 

The  plunger  elevator  made  by  the  Standard  Plunger  Elevator  Com- 
pany differs  in  many  details  from  the  machine  made  by  the  Otis  com- 
pany. The  principal  differences  are  in  the  construction  of  the  valves,  and 
their  location  in  the  piping  system  connecting  the  lifting  cylinder  with 
the  pressure  tank.  The  general  arrangement  of  the  valves  and  piping 
is  shown  in  Fig.  232,  which  is  an  elevation  of  the  entire  elevator  appar- 
atus. The  valves  are  contained  in  two  horizontal  cylindrical  chambers,  one 
placed  above  the  other,  as  shown.  The  upper  cylinder  contains  the  main 
operating  valve  and  the  pilot  valve,  the  latter  located  at  the  right-hand 
end.  The  lower  cylinder  contains  the  two  automatic  stop  valves,  the  top 
stop  valve  being  in  the  left-hand  end  and  the  bottom  one  in  the  right- 
hand  end.  From  the  center  of  this  chamber  a  pipe  runs  to  the  upper  end 
of  the  lifting  cylinder.  The  two  valve  chambers  are  connected  with  each 
other  by  two  vertical  pipes  on  opposite  sides  of  the  center,  one  for  con- 
veying the  pressure  water  from  the  main  valve  to  the  lifting  cylinder  and 
the  other  for  conveying  the  discharge  water  from  the  lifting  cylinder  to 
the  discharge  tank. 

The  pressure  water  enters  the  upper  valve  chamber  through  the  supply 
pipe  on  the  left,  and  passing  through  the  main  valve  flows  down  through 
the  left-side  pipe  connection  to  and  through  the  top  automatic  stop  valve 
and  into  the  pipe  that  leads  to  the  lifting  cylinder,  and  thus  forces  the 
plunger  and  the  car  upward.  On  the  down  trip  the  water  returns  from 
the  lifting  cylinder  to  the  lower  valve  chamber,  and  then  passing  through 
the  down  automatic  stop  valve  on  the  right  enters  the  right-side  pipe  con- 
nection that  leads  to  the  main  valve  chamber,  and  passing  through  the 
main  valve  reaches  the  discharge  pipe.  In  the  Otis  machine,  the  auto- 
matic stop  valves  are  placed  in  the  pipe  lines  outside  of  the  main  valve, 
so  that  the  pressure  water  passes  through  the  top  automatic  valve  before 
it  reaches  the  main  valve ;  and  when  the  water  is  discharged  as  the  eleva- 
tor runs  down,  it  first  passes  through  the  main  valve  and  then  through  the 
down  automatic  stop  valve.  In  the  Standard  elevator  the  arrangement  is 
just  the  opposite  of  this,  the  pressure  water  passing  through  the  main 

279 


280  HYDRAULIC  ELEVATORS 

valve  first  and  then  through  the  top  automatic  stop  valve,  thence  flowing 
into  the  cylinder;  from  the  cylinder  it  flows  through  the  down  automatic 
stop  valve  and  then  through  the  main  valve.  One  arrangement  is  as  good 
as  the  other,  and  neither  one  would  be  improved  or  injured  by  changing 
it  to  the  other  arrangement. 

In  the  Otis  plunger  the  automatic  stop  valves  are  actuated  by  station- 
ary or  standing  ropes,  the  upper  ends  being  fastened  to  the  overhead 
beams  of  the  elevator  well,  and  the  lower  ends  to  the  valve  levers.  In 
Fig.  232  the  stop  valves  are  actuated  by  running  ropes,  the  ends  of  which 
are  fastened  to  the  top  and  bottom  of  the  elevator  car.  The  rope  A, 
which  is  attached  to  the  under  side  of  the  car  on  the  left-hand  side,  runs 
down  to  and  around  a  sheave  mounted  on  the  end  of  the  lever  L'  that 
actuates  the  down  stop  valve.  From  this  sheave  the  rope  runs  up  to 
the  top  of  the  elevator  well  to  and  around  a  sheave,  and  then  runs  down  to 
the  top  of  the  car  to  which  it  is  fastened  on  the  right-hand  side.  The  rope 
B  is  secured  to  the  under  side  of  the  car  on  the  right,  at  B' ',  and  then 
runs  straight  down  to  and  around  the  sheave  on  the  end  of  the  lever 
L  of  the  top  stop  valve,  and  thence  up  to  the  top  of  the  elevator  well, 
over  a  sheave  there  and  down  to  the  left  side  of  the  top  of  the  elevator 
car,  where  it  is  made  fast.  From  this  arrangement  of  the  ropes  it  can 
be  seen  that  when  the  car  runs  down  the  down-stop  rope  A  will  draw  up 
lever  L{ ',  and  when  the  car  runs  upward,  rope  B  will  draw  up  lever  L 
of  the  top  stop  valve.  The  distance  through  which  the  levers  L  and 
L'  are  raised  by  the  ropes  can  be  varied  by  shifting  the  left-hand 
points  of  attachment  of  the  ropes  on  the  car  in  one  direction  or  the  other ; 
shifting  them  farther  to  the  left,  as  the  drawing  is  made,  increases  the 
movement  of  the  levers. 

The  pilot  valve  is  operated  by  a  standing-rope  system,  the  ropes  pass- 
ing around  sheaves  C  at  the  bottom  of  the  well  and  other  sheaves  C 
at  the  top.  These  latter  sheaves  are  mounted  on  a  frame  that  is  forced 
upward  by  a  spring  contained  in  the  cylinder  shown  below  the  sheaves. 
This  maintains  the  proper  tension  on  the  ropes.  The  ropes  pass  around 
the  sheaves  D  carried  in  a  frame  mounted  on  shaft  E  under  the  car,  and 
to  this  shaft  the  car  lever  F  is  secured ;  by  moving  this  lever  in  one  direc- 
tion or  the  other  the  pilot-valve  lever  D'  is  raised  or  depressed,  and  the 
car  travel  is  thereby  controlled. 

CONSTRUCTION  AND  OPERATION  OF  VALVES. 

The  construction  and  operation  of  the  valves  of  the  system  shown  in 
Fig.  232  are  indicated  by  Fig.  233,  which  is  a  sectional  elevation  parallel 
with  the  axis  of  the  valve  rods,  and  shows  the  general  construction  and 
positions  of  all  the  valves.  The  main  valve  consists  of  five  pistons  Q, 


Top  Automati 
Stop  Valve 


FIG.  233 


281 


282 


HYDRAULIC  ELEVATORS 


R,  R',  T  and  T ' ,  the  first  of  which  acts  as  a  motor  to  move  the  valve, 
in  the  same  way  as  in  all  other  pilot-valve  constructions.  The  main 
valve  is  shown  in  the  closed  or  stop  position.  The  automatic  stop  valves 
in  the  lower  cylinder  are  indicated  by  the  letters  Y  (the  down  stop)  and 
Z  (the  up  stop). 

In  all  types  of  pilot  valve,  the  movement  of  the  main  valve  acts  to 
return  the  pilot  to  the  closed  position,  and  in  most  of  the  arrangements 
thus  far  shown  the  way  in  which  this  result  is  produced  is  easily  seen, 


FIG.  233 

but  in  this  valve  it  is  not  so  apparent.  The  part  U  at  the  right-hand 
end  of  the  main  valve  stem  is  a  rack,  and  P'  is  a  pinion  meshing  with  this 
rack.  If  the  pilot-valve  lever  X  is  raised,  the  connecting  rod  K  will  lift 
the  nut  frame  L  and  thereby  raise  the  pilot  valve,  allowing  water  to  flow 
in  from  the  main  supply  pipe  5  through  pipe  D;  passing  through  the  pilot 
valve,  it  flows  through  pipe  P  to  the  end  M  C  of  the  main  valve  chamber, 
where  it  forces  piston  Q  to  the  right.  This  movement  will  rotate  the 
pinion  P'  so  as  to  run  the  screw  at  the  upper  end  out  of  nut  L  and  force 
P'  down  and  with  it  the  pilot  valve,  until  the  latter  reaches  the  closed  posi- 
tion when  the  movement  of  Q  to  the  right  will  stop  as  no  more  water  will 
flow  into  the  space  M  C.  If  the  pilot-valve  lever  X  is  depressed,  the 
water  in  space  M  C  will  flow  out  through  pipe  P  in  the  direction  indicated 
by  the  dotted  arrows  and  upon  reaching  the  pilot  valve  will  pass  through 
it.  and  into  pipe  E" ' ,  which  leads  to  the  main  discharge  pipe  E'.  The 


THE  "STANDARD"  PLUNC.ER  ELEVATOR 


283 


movement  of  the  rack  U  will  then  be  in  the  opposite  direction  and  pinion 
P'  will  be  rotated  so  that  the  pilot  valve  will  be  raised  to  the  closed  posi- 
tion. 

When  the  main  valve  pistons  are  moved  to  the  left  by  the  downward 
movement  of  the  lever  X,  the  ports  of. the  supply  pipe  S  will  be  opened 
by  piston  R  and  water  will  flow  through  as  indicated  by  the  arrows,  to 


FIG.  234 

the  pipe  Sr  and  thence  through  the  uncovered  ports  of  the  lower  cham- 
ber to  pipe  S"  and  to  the  cylinder,  causing  the  car  to  run  upward. 
The  top  stop  valve  Z  will  be  in  the  open  position  as  shown,  and  if  the  car 
is  at  the  lower  floor  the  down  stop  valve  Y  will  be  closed.  As  soon  as  the 
car  begins  to  move  upward,  lever  W  of  the  down  stop  valve  will  descend 
and  gradually  open  valve  Y  while  the  car  is  rising  through  the  first  ten 
or  fifteen  feet.  When  the  car  reaches  the  top  of  the  well,  if  the  operator 
does  not  move  the  car  lever  to  stop  the  car,  lever  V  will  be  gradually 


284  HYDRAULIC  ELEVATORS 

raised  and  the  stop  valve  Z  will  slowly  close  and  stop  the  car  at  the  top 
floor.  On  the  down  trip  the  down  stop  valve  Y  will  be  opened,  and  as 
soon  as  the  main  valve  is  shifted  to  the  right  far  enough  to  cause  piston 
T  to  uncover  the  ports  opposite  pipe  E,  tJbe  water  will  flow  out  of  the 
cylinder  through  pipe  S"  into  pipe  E,  through  the  main  valve  to  pipe  E' , 
and  the  car  will  run  down.  When  it  approaches  the  lower  floor  the 
stop  valve  Y  will  be  slowly  closed  by  the  lifting  of  lever  W,  being  closed 
entirely  when  the  car  reaches  the  level  of  the  lower  floor. 

Fig.  233  is  one  of  the  early  designs  used  by  the  Standard  company, 
and  is  considerably  different  from  the  valves  used  with  elevators  installed 
at  the  present  time.  The  latest  design  of  valve  is  shown  in  the  drawings 
Fig.  234,  which  gives  a  plan  view  and  a  sectional  elevation.  The  pilot 
valve  is  substantially  the  same  as  in  Fig.  233,  but  the  main  valve  is 
materially  different  and  the  automatic  stop  valves  are  turned  around 
so  that  the  cranks  that  move  them  are  in  the  center,  instead  of  at  the  ends 
of  the  valve  chamber.  The  main  valve  consists  of  four  pistons,  and  the 
force  for  moving  them  is  obtained  by  making  the  piston  T'  of  smaller 
area  than  the  other  three,  so  that  this  piston  virtually  takes  the  place  of 
piston  Q  in  Fig.  233.  The  flow  of  water  through  the  valves  is  as  indi- 
cated by  the  arrows ;  the  port  M  at  the  center  of  the  automatic  stop  valve 
chamber  leads  to  the  lifting  cylinder.  The  two  levers  W  and  V  which 
move  the  automatic  stop  valves  swing  around  shaft  A  but  only  the  lever 
V  is  keyed  to  it.  The  other  lever  swings  freely  around  shaft  A  and 
through  the  gear  segments  D'  and  D"  moves  shaft  B  and  thereby  actuates 
the  stop  valve  Y.  This  arrangement  of  the  levers  is  made  somewhat 
clearer  by  looking  at  the  plan  view  in  Fig.  234,  which  also  shows  the 
actual  position  of  the  pipe  connections  between  the  pilot  valve  and  the 
main  valve  chamber,  and  as  these  are  lettered  the  same  as  in  Fig.  233,  the 
direction  of  flow  of  water  through  them  can  be  readily  understood. 

Each  stop  valve  is  provided  with  a  cylindrical  extension  marked  G  G' , 
the  same  as  in  Fig.  233,  and  this  extension  acts  as  a  throttle  when  the 
valve  moves  far  enough  backward.  The  valve  Y  is  shown  closed  and 
valve  Z  open;  through  the  latter  water  passes  through  a  port  that 
separates  it  from  the  extension  G.  If  the  valves  are  in  perfect  working 
order,  the  valve  never  moves  farther  away  from  the  center  than  the  posi- 
tion in  which  it  is  drawn,  but  if  the  rope  that  actuates  the  lever  V 
should  break,  the  lever  would  drop  and  carry  the  valve  Z  away  from  the 
center  until  its  end  touched  the  head  of  the  valve  chamber,  and  then  the 
throttle  G  would  cover  the  ports  leading  in  from  pipe  S'.  From  this 
it  is  evident  that  the  throttles  G  G'  are  simply  safety  devices  that  never 
come  into  action  except  in  the  case  of  some  disarrangement  of  the  ropes 
that  lift  the  levers  V  and  W ';  they  are  not  made  a  tight  fit,  but  are  loose 


THE  "STANDARD''  PLUNGER  ELEVATOR  285 

enough  to  permit  water  to  leak  through  them  fast  enough  to  enable  the  car 
to  move  very  slowly,  so  that  if  the  actuating  rope  should  break  when  the 
car  is  half  way  up  the  elevator  well,  it  would  not  be  held  there  but  would 
slowly  run  to  the  end  of  the  trip. 

The  valves  F  and  Z  are  made  with  an  opening  through  the  center  so 
that  water  may  circulate  through  them  between  the  end  spaces  and  the 
crank  chamber  at  the  center  of  the  valve  chamber.  This  construction  is 
provided  so  that  the  valves  may  move  freely.  In  each  one  of  these  open- 
ings a  check  valve  C  or  C'  is  provided  to  prevent  the  valve  from  moving 
away  from  the  center  so  rapidly,  if  the  rope  that  actuates  the  lever  should 
break,  as  to  cause  the  throttle  to  stop  the  flow  of  water  too  suddenly. 
The  check  valves  are  so  proportioned  that  when  the  water  flows  through 
them  to  the  space  back  of  the  stop  valve,  the  opening  is  large  enough 
to  afford  it  free  passage,  but  when  the  water  is  forced  out  of  this  space, 
it  has  to  pass  through  small  holes  made  in  the  check  valves  and  these  are 
of  such  size  that  the  weight  of  the  lever  V  or  W  cannot  move  the  throttle 
G  or  Gr  back  over  the  ports  so  rapidly  as  to  produce  a  too  sudden  reduc- 
tion of  the  car  speed. 

It  will  be  noticed  that  an  outlet  M'  is  shown  in  broken  lines.  This 
outlet  is  not  always  used,  but  when  used  its  object  is  to  economize  pres- 
sure water,  and  also  to  prevent  the  plunger  from  rising  above  the  water 
in  the  cylinder  if  a  too  rapid  stop  is  made  on  an  up  trip. 


CHAPTER  XL 

OPERATION  OF  THE  PILOT  AND  MAIN  VALVES ;  HOW  THE 
ADJUSTMENTS  ARE  MADE 

In  order  to  explain  the  operation  of  the  pilot  valve  shown  in  Figs. 
233  and  234,  larger  drawings,  Figs.  235,  236  and  237,  are  shown,  the 


FIG.  235 

first  being  a  vertical  longitudinal  section,  the  same  as  that  shown  in 
Figs.  233  and  234,  but  on  a  larger  scale,  the  second  a  cross-section  through 
the  center  of  the  pilot  valve,  and  as  seen  looking  at  Fig.  235  from  the 
right  side  Fig.  237  is  a  top  view  showing  a  section  through  the  upper 

286 


PILOT  AND  MAIN  VALVES 


end  of  the  pilot  valve  on  lines  X  X  in  Figs.  235  and  236.  To  the  operat- 
ing lever  C  is  attached  a  connecting  rod  K.  This  rod  guides  a  nut  L 
that  runs  on  a  screw  L'  cut  on  the  upper  end  of  a  shaft  L" '.  This  shaft 
also  carries  a  pinion  P'  that  meshes  in  a  rack  V  mounted  upon  the  end 
of  the  main  valve  stem.  Below  this  pinion  are  two  spiral  cams  a  and  a', 
also  mounted  on  the  shaft  L" .  Between  these  cams  there  are  two  similar 
cams  b  and  b'  fastened  to  the  plate  b" .  The  shaft  L"  is  connected  with 


FIG.  236 

the  lower  end  of  the  pilot  valve  by  an  arm  D;  hence,  if  the  lever  C  is 
raised  the  pilot  valve  is  raised,  and  if  the  lever  is  depressed,  the  valve  is 
likewise  depressed.  When  lever  C  is  raised,  the  cup  packing  O  at  the 
upper  end  of  the  pilot  valve  will  be  raised,  and  water  from  the  supply 
pipe  will  pass  through  the  opening  made  by  lifting  the  cup  O  and  pass 
to  the  central  pipe  that  connects  with  the  back  end  of  the  main  valve 
cylinder;  that  is,  to  the  pipe  P  of  Figs.  233  and  234.  This  water  will 
move  the  main  valve  to  the  right,  and  the  rack  V  will  rotate  the  pinion  P' 


288 


HYDRAULIC  ELEVATORS 


so  as  to  cause  the  screw  L'  to  run  down  in  nut  L,  carrying  the  pilot  valve 
downward  and  returning  the  cup  packing  O  to  the  position  in  which  it 
is  shown  in  Fig.  236.  This  will  stop  the  flow  of  water  into  the  main 
valve  cylinder  and  thereby  stop  the  movement  of  the  valve  to 
the  right. 

The  movement  of  the  rack  V  must  be  sufficient  to  return  the  packing 
O  to  its  seat,  so  that  if  lever  C  is  raised  a  short  distance  the  movement 
of  rack  V  to  the  right  will  be  small,  and  if  the  lever  is  raised  as  high  as 
it  can  be  moved,  the  rack  will  travel  to  the  right  its  maximum  distance. 
In  other  words,  the  amount  of  opening  of  the  main  valve  must  be  directly 


FIG.  237 


proportional  to  the  distance  through  which  lever  C  is  moved.  Movement 
of  lever  C  downward  will  have  the  same  effect,  but  in  the  reverse  direc- 
tion, for  then  the  pilot  valve  will  be  depressed  and  the  lower  cup  packing 
B  will  be  drawn  down  so  that  the  water  in  the  back  end  of  the  main 
valve  cylinder,  returning  through  pipe  P,  will  be  able  to  flow  into  the 
pilot  valve  through  the  central  inlet,  and  passing  down  to  the  lower  end 
will  enter  the  valve  cylinder  and  run  up  past  cup  B  and  out  into  the 
discharge  pipe.  As  soon  as  water  begins  to  flow  out  of  the  back  end  of 
the  main  valve  cylinder,  the  main  valve  will  move  to  the  left,  and  rack  V 
will  rotate  pinion  P'  in  the  direction  to  work  the  screw  L'  upward  in 
nut  L,  thereby  lifting  the  pilot  valve  and  returning  the  cup  packing  B 
to  its  seat  to  close  the  outlet  and  prevent  further  movement  of  the 
main  valve. 

The  stationary  cams  b  and  &',  in  conjunction  with  the  cams  a  and  a' 
on  the  shaft  L" ',  are  provided  to  prevent  sudden  reversals  of  the  elevator. 


PILOT  AND  MAIN  VALVES  289 

/ . 

If  these  were  not  used,  the  operator  could  swing  the  car  lever  over 
from  the  full-speed  position  upward  to  the  downward  full-speed 
position  almost  instantly,  and  as  the  car  motion  could  not  be 
reversed  in  so  short  an  interval  of  time,  the  plunger  would  be 
drawn  away  from  the  water,  with  the  effects  already  explained.  With 
the  cams  arranged  as  shown,  the  operator  can  only  move  the  car  lever 
back  to  the  stop  position ;  it  will  not  move  farther  until  the  pilot  and  the 
main  valves  have  been  brought  back  to  the  stop  position.  The  cams 
a,  a'  and  b,  b'  are  made  of  the  same  pitch  as  the  screw  Lf,  and  the  dis- 
tance between  a  and  b  or  a'  and  b',  when  in  the  stop  position,  measured 
parallel  with  the  axis  of  the  shaft  L" ',  is  equal  to  the  full  stroke  of  the 
pilot  valve ;  therefore,  if  lever  C  is  moved  its  full  swing  in  either  direc- 
tion, the  corresponding  cam  on  the  shaft  will  bring  up  against  the  sta- 
tionary cam  opposite  it,  and  the  other  cam  on  the  shaft  will  be  drawn 
to  double  the  initial  distance  from  the  other  stationary  cam.  As  soon  as 
the  main  valve  begins  to  move  it  will  rotate  the  last-named  shaft  cam 
around  over  the  high  point  of  the  stationary  cam,  and  as  the  thread  of 
screw  L'  and  the  cam  pitch  are  the  same,  the  distance  separating  the 
cams  will  be  just  equal  to  the  distance  through  which  the  shaft  L"  has 
been  raised;  hence,  if  the  operator  moves  the  car  lever  in  the  reverse 
direction,  he  can  only  move  it  as  far  as  he  did  when  starting,  that  is, 
back  to  the  stop  position,  but  no  farther.  If,  after  the  operator  has 
moved  the  car  lever  to  the  central  position  and  finds  that  it  will  go  no 
farther,  he  persists  in  keeping  up  the  pressure  on  it,  when  the  shaft  cam 
passes  beyond  the  high  point  c  or  c'  of  the  stationary  cam,  the  lever  will 
be  freed  and  the  operator  will  be  able  to  move  it  until  the  shaft  cam 
strikes  the  stationary  cam,  but  this  will  be  after  the  pilot  and  main  valve 
have  been  brought  to  the  stop  position,  and  the  elevator  has  likewise 
stopped. 

In  addition  to  the  cams  a,  a'  and  b,  b',  several  adjusting  plugs  are 
provided  to  regulate  the  flow  of  water  through  the  pilot  valve.  Looking 
at  Figs.  235  and  236,  it  will  be  seen  that  at  the  upper  end  of  the  pilot 
valve  there  is  a  plunger  N  that  slides  through  a  sleeve  A,  and  at  the 
lower  end  there  is  another  plunger  N'  that  slides  through  a  sleeve  A'. 
These  sleeves  have  three  port  holes  set  on  a  diagonal  line  and  opposite 
each  port  there  is  an  adjusting  plug  A" ;  the  positions  of  these  are  shown 
in  Fig.  237.  By  means  of  these  screws  the  opening  through  the  port 
holes  can  be  varied  to  any  extent  that  may  be  desired.  In  addition  to 
these  adjusting  plugs  there  are  two  others  that  screw  into  the  holes  F', 
shown  in  Fig.  236.  The  upper  plug  F'  controls  the  flow  of  pressure 
water  into  the  space  at  the  back  end  of  the  main  valve  cylinder,  and  the 
lower  plug  controls  the  flow  of  the  discharged  water.  From  Fig.  234  it 


290  HYDRAULIC  ELEVATORS 

can  be  seen  that  in  order  to  start  the  elevator  on  the  up  trip  with  this 
type  of  valve  it  is  necessary  to  move  the  main  valves  to  the  right  to 
allow  water  from  the  supply  pipe  to  pass  into  the  cylinder.  To  move 
the  main  valve  to  the  right,  pressure  water  has  to  be  admitted  to  the 
space  back  of  the  piston  Q.  To  start  the  car  on  the  down  trip  the  main 
valves  have  to  be  moved  to  the  left,  in  order  that  the  piston  R  may 
uncover  the  ports  opposite  the  pipe  E  and  permit  water  to  escape  from 
the  cylinder.  To  move  the  main  valves  to  the  left,  water  must  escape 
from  the  space  back  of  the  piston  Q.  To  stop  the  car  on  the  up  trip 
the  main  valve  must  move  to  the  left,  hence  water  must  be  drawn  from 
the  space  back  of  the  piston  Q,  and  to  stop  on  the  down  trip  the  main 
valve  must  be  moved  to  the  right;  hence  water  must  be  admitted  to  the 
space  back  of  the  piston.  The  rate  of  flow  through  the  pilot  valve  from 
the  supply  pipe  to  the  central  outlet  that  connects  with  the  pipe  leading 
to  the  space  back  of  the  piston  Q  is  controlled  by  the  adjusting  plugs  A" 
opposite  the  port  holes  in  the  upper  sleeve  .A,  Fig.  236,  and  also  by  the 
plug  in  the  hole  F'.  In  starting  the  car  on  the  upward  trip  it  is  necessary 
to  open  the  main  valve  quickly,  to  get  the  full  pressure  in  the  lifting 
cylinder,  because  the  load  has  to  be  started  from  rest.  In  stopping  on 
the  down  trip  it  is  necessary  to  shut  off  the  flow  quickly  because  the 
momentum  of  the  downward  moving  car  and  plunger  will  force  a  large 
quantity  of  water  through  a  small  opening;  therefore,  the  adjustment 
that  is  proper  for  giving  the  car  rapid  acceleration  in  starting  on  the 
up  trip  is  also  proper  to  give  rapid  retardation  in  stopping  on  the  down 
trip,  and  this  adjustment  is  made  by  the  same  set  of  adjusting  plugs, 
namely,  those  at  the  top  of  the  pilot  valve. 

In  starting  on  the  down  trip  it  is  necessary  to  open  the  valve  slowly,  so 
that  the  weight  of  the  car  and  plunger  may  not  force  the  water  out  of 
the  cylinder  so  fast  as  to  cause  the  car  to  run  down  too  rapidly;  in 
stopping  on  the  up  trip,  also,  it  is  necessary  to  close  the.  main  valve 
slowly,  in  order  not  to  stop  the  flow  of  water  into  the  cylinder  faster 
than  the  momentum  of  the  counterbalance  will  permit  the  car  to  stop, 
otherwise  the  plunger  will  be  lifted  from  the  water.  As  already 
explained,  the  car  is  started  on  the  down  trip  and  stopped  on  the  up 
trip  by  letting  out  the  water  in  the  space  back  of  the  piston  Q,  and  in 
escaping  it  passes  by  the  adjusting  plugs  F  and  A"  at  the  lower  end  of 
the  pilot  valve ;  hence,  the  adjustment  of  these  that  is  proper  for  making 
stops  on  up  trips  is  also  proper  for  starting  on  down  trips.  When  the 
lever  C  is  moved  the  full  distance  the  pilot  valve  is  given  its  full  stroke, 
and  the  three  port  holes  in  the  sleeve  A  opposite  the  plugs  A"  are 
uncovered  by  the  plunger  N,  so  that  the  maximum  quantity  of  water 
flows  through  the  pilot  valve.  When  the  lever  is  moved  less  than  the  full 


PILOT  AND  MAIN  VALVES  291 

distance,  the  pilot  valve  is  given  less  than  the  full  stroke,  and  all  the 
port  holes  in  A  are  not  uncovered  by  the  plunger  N.  Therefore,  if  the 
operator  desires  to  get  under  full  headway  in  the  shortest  time  possible 
all  he  has  to  do  is  to  swing  the  operating  lever  all  the  way  over,  and 
the  speed  of  the  car  will  be  accelerated  at  the  highest  rate  for  which  the 
pilot  valve  is  adjusted.  If  the  operator  does  not  desire  to  run  at  full 
speed  he  moves  the  car  lever  part  of  the  distance,  and  the  plunger  N  is 
not  raised  high  enough  to  uncover  all  the  port  holes  in  the  sleeve  A,  so 
that  the  car  will  not  only  run  at  a  reduced  speed,  but  will  also  get  under 
way  more  slowly. 

THE  VALVES  OF  THE  "STANDARD"   PLUNGER   FREIGHT   ELEVATOR. 

For  the  operation  of  freight  elevators  the  Standard  Plunger  Elevator 
Company  provides  simple  hand-rope-operated  valves.  These  valves  are 
made  to  be  moved  by  a  lever  if  the  car  speed  is  very  low,  by  single- 
geared  rack  and  pinion  for  moderate  speed  and  by  a  double-geared  rack 
and  pinion  for  high  velocity ;  they  are  also  of  the  balanced  and  unbalanced 
types.  An  unbalanced-type  valve  with  double-geared  rack  and  pinion  is 
shown  in  Fig.  238,  and  a  balanced  valve  of  similar  design  in  Fig.  239. 
The  unbalanced  valve  is  not,  strictly  speaking,  unbalanced ;  it  is  only  so 
when  used  in  an  installation  where  the  discharge  tank  is  located  higher 
up  than  the  valve.  If  the  pressure  acting  upward  against  the  under  side 
of  piston  B  is  the  same  as  the  pressure  acting  downward  on  piston  D  the 
valve  will  be  perfectly  balanced,  because  the  pressure  from  the  supply 
tank  acts  equally  against  the  under  side  of  D  and  the  upper  side  of  C. 
The  pressure  of  the  atmosphere  acts  on  top  of  D,  and  if  the  discharge 
tank  is  on  a  level  with  the  valve,  the  same  pressure,  or  nearly  so,  will 
act  under  B;  therefore,  the  valve  will  be  fully  balanced.  If,  however,  the 
discharge  tank  is  several  feet  above  the  valve,  the  pressure  acting-  under 
B  will  be  greater  than  that  acting  down  on  D,  and  the  valve  will  not  be 
fully  balanced.  The  valve  in  Fig.  239  is  fully  balanced,  no  matter 
whether  there  is  a  back  pressure  from  the  discharge  tank  or  not, 
because  this  pressure  acts  equally  against  the  under  side  of  piston  B 
and  the  upper  side  of  piston  A;  and  the  pressure  of  the  atmosphere  acts 
equally  against  the  under  side  of  A  and  the  upper  side  of  D.  For  slow- 
speed  cars  this  type  of  valve  is  better  than  the  complicated  pilot  valve, 
with  its  accompanying  automatic  stop  valves,  because  it  accomplishes 
all  that  the  more  complicated  and  expensive  construction  can  accomplish, 
and,  being  far  more  simple,  is  not  as  liable  to  get  out  of  order.  It  is 
not  desirable  for  fast-running  elevators,  however,  because  the  movement 
of  the  car  cannot  be  controlled  with  as  great  precision  by  means  of  the 
hand  rope,  owing  to  the  rapid  motion  of  the  car  and  the  long  distance 
through  which  the  rope  has  to  be  pulled  to  effect  a  stop.  This  is  the 


292 


HYDRAULIC  ELEVATORS 


only  advantage  of  the  pilot  valve  with  car-lever  control.  With  it  a 
fast-running  car  can  be  stopped  even  with  the  floors  of  the  building  by 
anybody  after  a  few  days'  practice  but  with  the  hand-rope  control  only 


FG.  238  FIG.  239 

the  most  experienced  car  operators  can  obtain  results  that  are  at  all 
satisfactory  in  large  office  buildings. 

LIFTING-CYLINDER  DESIGN. 

The  casting  that  forms  the  upper  end  of  the  lifting  cylinder  is  made 
in   several   designs   by   the   Standard   Plunger   Elevator   Company,   one 


PILOT  AND  MAIN  VALVES 


293 


design  being  shown  in  Fig.  240,  which  is  a  vertical  sectional  view.  The 
main  casting  is  marked  A;  at  B  is  the  stuffing-box,  and  C  is  the  upper 
end  of  the  top-pipe  section  of  the  cylinder.  The  casting  A  is  provided 
with  a  brass  sleeve  D  that  fits  the  lifting  plunger  and  serves  as  a  guide 
for  it.  This  sleeve  fits  tightly  at  the  upper  end  all  the  way  around  the 


f 


FIG.   240 


FIG.  241 


circle,  but  at  the  lower  end  it  is  held  in  the  central  position  by  means  of 
radial  webs  A'  A',  which  are  narrow  enough  to  afford  free  passage  for 
the  water,  but  at  the  same  time  firm  enough  to  give  the  sleeve  proper 
support.  The  stuffing-box  B  is  provided  with  a  gland  E  pressed  down 
by  studs  F.  The  box  itself  is  secured  to  A  by  studs  F'.  The  packing 
may  be  of  hemp,  or  any  good,  soft  packing  material,  but  usually  a  special 


294 


HYDRAULIC  ELEVATORS 


design  of  double  cup  packing  is  used.  The  stuffing-box  is  made  with  a 
rim  B'  which  forms  a  basin  to  catch  any  water  that  may  leak  out  of  the 
cylinder.  A  drain  pipe  B"  is  tapped  in  on  one  side  to  remove  the  water 
as  fast  as  it  accumulates. 

Fig.  241  is  a  vertical  section  of  the  plunger  end  used  in  connection 
with  the  cylinder  top  shown  in  Fig.  240.  This  end  is  made  up  of  the 
parts  A,  B,  D  and  F,  which  are  held  together  by  a  long  central  bolt  G. 
The  upper  part  A  is  screwed  into  the  lower  section  of  the  plunger  P. 
The  parts  B,  D  and  F  are  pressed  tightly  against  each  other  by  the  bolt  G 
and  nut  C,  and  all  these  parts  are  held  firmly  against  A  by  screwing  the 
end  of  G  into  A,  as  shown.  The  parts  A  and  D  are  made  of  cast  iron, 
which  would  rust  in  time,  as  this  part  of  the  plunger  does  not  ordinarily 


Key  way 


-Key  way 


FIG.  242  FIG.  24* 

run  up  into  the  sleeve  D  of  the  cylinder-top  casting.  On  this  account 
these  parts  are  incased  in  brass,  as  shown  at  A'  and  E.  The  construc- 
tion of  the  upper  part  A  is  simple,  but  the  part  B  is  better  illustrated  in 
Figs.  242  and  243,  the  first  being  a  view  similar  to  that  in  Fig.  241,  the 
second  a  horizontal  section  through  L  L.  This  piece,  it  will  be  noticed, 
has  four  holes  marked  B'  that  radiate  from  a  central  opening  larger  in 
diameter  than  the  bolt  G  opposite  and  below  these  holes.  Above  the 
holes,  the  center  hole  of  B  fits  the  bolt  G}  and  the  latter  is  kept  from 
turning  in  it  by  two  keys. 

The  part  D  is  simply  a  cylindrical  piece  shaped  at  its  ends  to  fit  over 
a  projection  depending  from  the  under  side  of  B  and  into  a  recess  bored 
in  the  upper  end  of  F,  this  construction  being  designed  to  bring  the  parts 
central  when  the  bolt  G  is  screwed  up  into  the  part  A.  It  will  be 
noticed  that  a  screw  £  is  run  into  the  joint  between  B  and  A  so  these 
two  parts  cannot  turn  around  with  reference  to  each  other  and  work  the 
bolt  G  loose.  The  keys  prevent  G  from  turning  in  B,  so  all  these  parts 
are  securely  locked;  therefore,  the  nut  C  cannot  turn,  but  even  if  it  did 


PILOT  AND  MAIN  VALVES 


295 


it  could  do  no  harm  because  after  bolt  G  is  screwed  up  tightly  in  A  the 
nut  is  not  depended  upon ;  in  fact,  its  principal  object  is  to  hold  the  lower 
parts  together  when  they  are  disconnected  from  part  A.  The  lower 
casting  F  has  a  longitudinal  opening  through  it  considerably  larger  than 
the  bolt  G,  and  this  opening  has  lateral  connections  with  the  exterior  of 
the  casting.  As  the  part  D  is  also  hollow,  there  is  a  free  passage  through 
the  end  of  the  plunger  from  the  bottom  of  the  casting  F  to  the  holes 
B'  Br  in  the  part  B.  The  object  of  this  construction  is  to  provide  positive 
means  for  stopping  the  upward  movement  of  the  elevator  car  before  it 


FIG.  244  FIG.  245 

reaches  the  overhead  beams,  if  for  any  reason  it  should  fail  to  stop  at 
the  upper  floor.  When  the  elevator  is  in  perfect  running  order,  the  top 
automatic  valve  will  stop  the  car  even  with  the  upper  floor,  and  then 
the  holes  B'  B'  will  be  some  distance  below  the  stuffing-box,  but  if  the 
stop  valve  fails  to  operate  and  the  car  continues  upward,  it  will  not  rise 
far  enough  to  strike  the  overhead  beams  before  the  holes  B'  will  pass 
above  the  stuffing-box,  and  the  water  in  the  cylinder  will  find  an  outlet, 
the  plunger  will  rise  no  farther. 

CONSTRUCTION  OF  PLUNGER  LOWER  CASTING. 

The  lower  casting  F  of  the  plunger  is  arranged  to  carry  the  guide 
brushes  H  that  hold  the  plunger  in  the  center  of  the  cylinder.  The  con- 
struction of  this  casting  and  the  way  in  which  the  brushes  are  held  in 
place  may  be  fully  understood  by  the  aid  of  the  two  horizontal  sections, 
Figs.  244  and  245,  taken  on  lines  N  N  and  MM,  Fig.  241.  These  two 
sectional  views  also  show  a  section  of  the  cylinder  C,  to  present  more 
clearly  the  relative  positions  of  the  several  parts.  In  Fig.  244  it  will  be 
seen  that  the  brushes  are  held  in  grooves  cast  lengthwise  of  the  casting 
F,  and  that  these  grooves  are  provided  with  flanges  a  along  their  inner 


296 


HYDRAULIC  ELEVATORS 


edges,  to  prevent  forcing  the  brushes  too  far  in  toward  the  center,  and 
other  short  flanges  F'  to  lock  them  in  position.  The  brush  back  is  made 
with  short  flanges  H'  that  slide  in  back  of  the  flanges  F'.  In  putting  the 


brush  in  position  it  is  raised  to  the  top  of  the  groove  and  then  pressed 
in  until  the  flanges  H'  can  be  forced  down  back  of  the  flanges  F',  then 
the  brush  is  driven  down  and  a  key  /,  Fig.  241,  is  put  in  above  the  brush 
to  prevent  it  from  jumping  up.  The  brush  is  forced  down  until  the  back 


PILOT  AND  MAIN  VALVES  297 

/ 

rests  hard  against  the  bottom  F"  of  the  side  grooves  in  casting  F.  The 
keys  /  are  not  driven  in  endwise,  but  sidewise,  that  is,  toward  the  center 
of  the  casting,  and,  when  in  position,  are  clinched  so  they  cannot  work  out. 
The  brushes  are  made  of  hard  spring-brass  wire,  about  No.  22  gage. 
The  back  is  of  babbitt  metal  and  is  cast  around  the  wires  to  hold  them 
firmly  in  position.  The  grooves  in  the  casting  F,  into  which  the  brush 
backs  fit,  are  not  machined,  but  are  simply  carefully  cast,  and  the  burs 
well  cleaned  off.  As  the  brush  back  is  soft,  there  is  no  difficulty  in 
forcing  it  into  place.  If  it  should  fit  too  tightly,  it  can  be  easily  shaved 
off  where  it  binds.  When  the  brushes  are  in  place  in  the  casting  F  the 
water  in  the  cylinder  can  reach  the  central  space  through  the  openings 
above  and  below  them,  and  also  through  the  joints  between  the  brush 
back  and  the  casting,  as  these  are  not  tight  fits. 

ANOTHER   DESIGN   OF  PLUNGER   END. 

Another  design  of  plunger  end  made  by  the  Standard  company  is 
shown  in  Fig.  246,  which  is  a  vertical  elevation  in  section,  showing  the 
plunger  at  its  highest  position,  that  is,  in  the  position  it  reaches  when  the 
car  is  even  with  the  upper  floor  of  the  building.  The  brushes  in  this 
case  are  held  by  the  bolts  B.  A  horizontal  section  through  the  lower 
end  of  the  casting  F  is  shown  in  Fig.  247,  from  which  it  will  be  seen 
that  there  are  only  three  brushes.  This  design  is  simpler  than  that  of 
Fig.  241,  but  it  is  not  as  perfect.  In  the  latter  if  the  car  overruns  the 
upper  limit  of  travel  the  holes  Bf  in  the  piece  B  will  pass  above  the 
stuffing-box  and  let  the  water  in  the  cylinder  flow  out  before  the  brushes 
reach  the  packing,  but  in  Fig.  246  it  can  be  seen  that  for  the  water  to 
escape  the  plunger  must  run  up  until  the  part  F'  of  the  casting  passes 
above  the  gland  E,  and  this  will  carry  the  upper  end  of  the  brushes  up 
into  the  stuffing.  If  the  latter  is  of  the  cup  type  it  may  not  be  damaged 
to  any  extent,  but  if  it  is  hemp  it  is  liable  to  be  pulled  out  of  place. 
This  plunger  end  cannot  be  used  with  the  cylinder  top  shown  in  Fig.  240, 
unless  there  is  so  much  head  room  above  the  elevator  car,  when  even 
with  the  top  floor,  as  to  permit  running  it  several  feet  higher  before  the 
casting  F  is  high  enough  to  permit  the  water  to  escape.  If  with  this 
cylinder  top  the  plunger  should  run  normally  as  high  as  it  is  drawn  in 
Fig.  246,  the  brushes  would  be  carried  up  into  the  brass  lining  D  and, 
by  being  bent  back  and  forth  at  every  trip,  would  soon  become  useless. 
The  cylinder  top  in  Fig.  246  is  very  much  shorter,  so  the  plunger  can 
rise  just  as  high  as  the  plunger  in  Fig.  241  can  rise  in  the  top  in  Fig. 
240,  without  running  the  brushes  up  into  the  bore  of  the  casting. 

PIPING  CONNECTIONS. 

The  pipe  connections  between  the  pump,  tanks  and  lifting  cylinder  of 
a  plunger-elevator  system  are  generally  very  simple,  but  in  some  of  the 


PILOT  AND  MAIN  VALVES  299 


higher-grade  passenger-elevator  installations  they  are  very  elaborate. 
The  arrangement  most  commonly  used  is  shown  in  Fig.  248.  In  this 
diagram  A  represents  the  lower  portion  of  the  elevator  car,  B  the 
plunger,  C  the  cylinder  and  D  D  spring  buffers  provided  for  the  car  to 
rest  on  when  at  the  lower  floor.  The  main  valve  is  shown  at  F,  and  is 
represented  as  of  the  simple  rack-and-single-gear  type.  The  discharge 
tank  is  at  G,  and  H  is  the  pressure  tank.  The  water  in  the  lifting 
cylinder  C  is  discharged  into  tank  G  through  pipe  L,  and  from  this  tank 
the  pump  draws  its  supply  through  the  suction  pipe  M.  The  discharge 
pipe  N  of  the  pump  leads  to  the  pressure  tank  H,  and  from  the  latter 
the  water  is  carried  to  the  lifting  cylinder  through  pipe  O.  In  order  to 
keep  the  necessary  quantity  of  air  in  the  pressure  tank  H  means  must 
be  provided  for  forcing  air  into  it  from  time  to  time,  to  replenish  that 
which  will  inevitably  escape  in  one  way  or  another.  In  large  installations, 
where  several  pumps  and  possibly  tanks  are  provided,  a  small  air  pump 
is  installed  to  furnish  the  compressed-air  supply,  but  in  smaller  plants 
the  pump  K  is  arranged  so  as  to  pump  air  whenever  necessary.  The 
pressure  tank  H  is  provided  with  a  glass  water  gage,  to  show  the  hight 
of  water  in  it,  and  also  with  a  pressure  gage.  In  addition,  a  pressure 
regulator  is  used  to  stop  the  pump  when  the  pressure  in  H  rises  to  the 
maximum,  and  to  start  it  when  the  pressure  falls  below  the  minimum. 

Fig.  248  shows  a  system  provided  with  a  full  complement  of  hand 
valves,  three  of  these  being  marked  V ,  V  and  V" .  There  are  two  more, 
one  in  the  pump  suction  and  one  in  the  pump-delivery  pipe  N.  When 
all  these  valves  are  placed  in  the  pipe  lines  the  inspection  of  the  several 
parts  of  the  apparatus  may  be  done  with  very  little  trouble.  If  it  is 
desired  to  examine  or  renew  the  cylinder  packing,  all  that  is  necessary  is 
to  run  the  car  down  to  the  lower  floor  and  then  close  valve  V.  If  the 
main  valve  is  to  be  taken  apart,  valves  V,  V  and  V"  are  closed.  To 
inspect  the  pressure  tank  H,  valve  V"  and  the  one  in  pipe  N  are  closed. 
If  repairs  or  inspection  of  the  pump  are  required  the  valves  in  pipes 
M  and  N  are  closed.  Thus  with  all  the  valves  shown  it  is  not  necessary 
to  draw  water  from  as  much  of  the  system  as  has  been  stated  in  previous 
chapters,  in  which  it  was  assumed  that  a  lesser  number  were  used.  If 
the  discharge  tank  G  is  lower  down  than  the  discharge  pipe  Q  valve 
V  may  be  dispensed  with  without  impairing  the  system,  and  we  may 
also  add  that  the  balanced  main  valve  F  can  be  replaced  by  one  of  the 
unbalanced  type,  such  as  shown  in  Fig.  238.  The  valve  in  the  suction 
pipe  M  may  also  be  discarded. 


CHAPTER  XLI 

CONSTRUCTION  AND  OPERATION  DETAILS  OF  THE  HIGH- 
EST TYPE  OF  PASSENGER  ELEVATOR  MADE  BY  THE 
STANDARD  PLUNGER  ELEVATOR  COMPANY 

For  the  highest  type  of  passenger  elevator  the  Standard  Plunger 
Elevator  Company  uses  the  system  shown  diagrammatically  in  Fig.  249. 
In  this  arrangement  it  will  be  noticed  that  the  discharge  tank  G  is  located 
several  floors  above  the  top  of  the  lifting  cylinder.  The  hight  of  the 


FIG.  249 

discharge  tank  varies  according  to  the  car  speed,  and  ranges  from  about 
40  feet  for  moderate  car  speed  to  double  this  hight  for  speeds  of  500 
or  600  feet  per  minute.  In  addition  to  setting  the  discharge  tank  at  an 
elevation,  the  discharge  pipe  Q  is  connected  with  the  inlet  pipe  P  through 
a  branch  R  in  which  is  inserted  a  check  valve  L.  The  object  of  this  pipe 
connection  is  twofold;  first,  it  prevents  drawing  the  plunger  away  from 
the  water  in  making  stops  on  the  upward  trips,  and,  second,  it  saves  a 

300 


HIGHEST  TYPE  OF  PASSENGER  ELEVATOR 


301 


considerable  quantity  of  pressure  water,  and  thereby  increases  the  effi- 
ciency of  the  apparatus.  The  valve  L  permits  water  to  flow  freely  from 
pipe  Q  into  the  cylinder,  but  prevents  water  from  passing  through  it 
from  the  cylinder  to  pipe  Q.  The  operation  of  the  system  is  as  follows: 
Suppose  the  elevator  is  running  up  at  full  speed  and  that  the  operating 
valve  F  is  closed  quickly;  then  the  momentum  of  the  counterbalance  D 


FIG.  250 

GENERAL    ARRANGEMENT    OF   ALL    THE     POSTS    OF    A    FIRST-CLASS    STANDARD 

PLUNGER   ELEVATOR. 

will  carry  the  car  upward  and  draw  the  plunger  away  from  the  water. 
This  would  be  the  effect  if  the  pipe  connection  R  were  not  provided,  but 
with  this  connection,  as  soon  as  the  plunger  begins  to  draw  away  from 
the  water,  the  vacuum  developed,  assisted  by  the  pressure  due  to  the 
elevation  of  the  tank  G,  will  cause  water  to  run  down  through  pipe  Q, 
valve  L  and  pipe  R  into  the  cylinder  and  keep  the  latter  full.  When  the 
plunger  comes  to  a  state  of  rest  there  is  no  empty  space  under  it,  and  as 


302  HYDRAULIC  ELEVATORS 

a  result  the  car  will  not  drop  down  as  would  be  the  case  if  water  could 
not  enter  the  cylinder. 

To  avoid  drawing  the  plunger  away  from  the  water  by  too  rapid  a 
valve  closure  on  the  upward  trips  when  the  simple  pipe  arrangement  of 
Fig.  248  is  used,  the  pilot  valve  is  adjusted  so  that  the  main  valve  cannot 
close  too  rapidly.  With  the  arrangement  of  Fig.  249  it  is  immaterial 
how  quickly  the  main  valve  is  closed,  providing  the  discharge  tank  is 
placed  high  enough  to  develop  as  much  pressure  as  may  be  necessary  to 
cause  water  to  flow  in  through  pipe  R  and  follow  up  the  plunger  as  fast 
as  it  moves  until  its  motion  is  arrested  by  the  greater  weight  of  the  car. 
All  the  water  that  is  drawn  into  the  cylinder  through  the  pipe  R  in 
making  stops  represents  energy  saved,  because  it  reduces  the  amount  of 
water  drawn  from  the  pressure  tank  H. 

It  is  not  practicable  in  all  buildings  to  set  a  discharge  tank  at  the 
desired  elevation,  and  in  such  cases  the  elevated  tank  G  must  be  replaced 
by  a  pressure  tank  located  in  the  basement.  A  system  of  this  kind  is 
shown  by  Fig.  250,  which  is  far  more  elaborate  than  Fig.  249,  and  shows 
every  detail  of  a  high-class  passenger-elevator  system.  Of  the  two  tanks 
shown,  the  top  one  is  the  pressure  and  the  lower  one  the  discharge  tank. 
The  pipe  Q  leads  to  an  inverted  U  consisting  of  two  legs,  as  shown,  the 
function  of  which  is  to  maintain  a  uniform  pressure  in  the  discharge 
tank.  This  U-pipe  is  extended  up  to  whatever  hight  may  be  necessary 
to  develop  the  required  pressure.  At  the  bend  at  the  top  a  short  vent 
pipe  is  provided,  which  is  open  at  the  upper  end,  so  as  to  prevent  the 
inverted  U  from  acting  as  a  siphon  and  drawing  the  water  out  of  the 
tank.  The  pilot-valve  lever  X  is  actuated  by  the  rope  /  which  runs  under 
stationary  sheaves  /'  at  the  bottom  and  over  and  under  the  two  sheaves  /" 
at  the  top  of  the  pit  at  the  bottom  of  the  shaft.  At  the  top  of  the 
building  the  rope  /  runs  over  other  sheaves,  as  shown  in  Fig.  251,  which 
represents  all  the  apparatus  at  the  upper  end  of  the  elevator  well,  and 
also  the  elevator  car.  The  lever  L  of  the  top  automatic  stop  valve  V  is 
actuated  by  rope  /,  and  the  lever  L'  of  the  down  automatic  stop  valve  V 
is  actuated  by  rope  /'.  The  points  of  attachment  of  these  ropes  to  the 
car  and  the  way  in  which  they  are  supported  at  the  top  of  the  elevator 
well  are  shown  in  Fig.  251. 

The  construction  of  the  car  buffers  is  shown  in  Fig.  250  at  H  H. 
The  counterbalance  buffers  are  of  similar  design,  but  are  not  generally 
provided  with  the  rubber  cushions  shown  below  the  spiral  springs  in  the 
car  buffers.  If  either  the  car  or  the  counterbalance  strikes  the  buffers 
running  at  a  high  speed,  the  latter  are  pushed  down  until  the  compression 
of  the  springs  arrests  the  motion.  The  stroke  of  the  buffers  depends  on 
the  speed  of  the  elevator,  being  made  greater  as  the  speed  increases.  The 


HIGHEST  TYPE  OF  PASSENGER  ELEVATOR 


303 


pump  on  the  right  draws  water  from  the  discharge  tank  through  the  suc- 
tion pipe  A,  and  delivers  into  the  pressure  tank  through  the  pipe  B.  The 
air  compressor  forces  air  into  the  discharge  tank  through  the  pipe  K 
and  into  the  pressure  tank  through  pipe  K'.  Each  tank  is  provided  with 


FIG.  251 

gages  to  show  the  pressure  and  the  water  level.  The  compressor  is  run 
only  occasionally,  when  the  air  supply  runs  low.  The  operation  of  the 
main  pump  is  controlled  by  a  pressure  regulator  N  which  is  connected 
with  the  pressure  tank  by  pipe  M.  This  regulator  controls  the  valve  in 
the  steam  pipe  and  thus  stops,  and  starts  the  pump  whenever  required 
by  the  variations  of  pressure  in  the  tank. 

The  operation  of  the  elevator  is  as  follows :  To  start  on  the  up  trip 
the  pilot-valve  lever  X  is  depressed,  causing  the  main  valve  to  be  moved 
to  the  left;  this  allows  water  to  pass  but  of  the  pressure  tank  through 
pipe  D  and  the  main  valve  to  the  connection  D',  thence  -through  the  top 
stop  valve  V  to  pipe  D" ',  and  to  the  cylinder  C,  forcing  the  plunger  P 
and  the  car  upward.  If  the  car  is  stopped  on  the  up  trip,  the  flow  of 
water  through  this  path  is  arrested  by  the  closing  of  the  main  valve,  and 


304 


HYDRAULIC  ELEVATORS 


if  the  latter  closes  so  rapidly  that  the  plunger  starts  to  rise  above  the 
water  in  the  cylinder,  then  the  water  in  the  lower  discharge  tank  flows 
upward  through  pipe  E" ,  to  and  through  check  valve  F  and  into  the 
chamber  of  the  down  stop  valve  F',  as  indicated  by  the  dotted  lines  back 
of  the  valve ;  from  here  it  runs  into  the  cylinder  until  the  car  stops.  In 
this  drawing  the  check  valve  F  is  the  same  as  the  valve  L  of  Fig.  249. 
When  the  car  is  running  upward  valve  V  is  open,  so  that  water  coming 


Discharge 


FIG.   252 

from  the  discharge  tank  through  check  valve  F  can  pass  through  it 
freely.  When  the  car  is  descending  the  down  stop  valve  V  is  open 
until  the  lower  floor  is  reached ;  consequently,  the  discharge  water  return- 
ing from  the  cylinder  C  can  pass  from  pipe  D"  to  the  connection  E, 
thence  through  the  main  valve  to  pipe  Er  and  to  the  discharge  tank 
through  pipe  E" '. 

The  automatic  stop  valves  shown  in  Fig.  250  are  arranged  slightly 
different  from  those  presented  in  Fig.  234,  this  arrangement  being  in  the 
position  of  the  shafts  upon  which  the  operating  levers  are  mounted.  The 


HIGHEST  TYPE  OF  PASSENGER  ELEVATOR 


305 


main  valve  also  is  provided  with  a  safety  feature  not  shown  on  other 
drawings.  These  points  of  difference  can  be  understood  by  inspection  of 
Fig.  252,  which  is  an  enlarged  sectional  view  of  the  main  and  stop  valves 
of  Fig.  250.  The  advantage  of  placing  the  shafts  B  and  A  one  above 
the  other  is  that  the  levers  W  and  V  can  be  attached  directly  to  them, 
while  in  the  construction  shown  by  Fig.  234  one  of  the  levers  swings  on 
the  shaft  of  the  opposite  lever,  and  imparts  movement  to  its  own  shaft 
through  spur-gear  segments.  In  Fig.  252  the  operation  of  the  stop  valves 
does  not  appear  to  be  practicable  because  it  looks  as  if  a  very  small 


OilPlp* 


FIG.  253 

movement  of  crank  V"  to  the  left  would  carry  it  into  crank  W" .  This 
difficulty  can  be  fully  cleared  up  by  the  aid  of  Fig.  253,  which  is  a 
vertical  section  at  right  angles  to  the  view  in  Fig.  252  and  passing 
through  the  centers  of  the  shafts  A  and  B.  Looking  at  this  drawing  it 
will  be  seen  that  the  cranks  V"  and  W"  are  made  so  that  they  can  swing 
past  each  other.  This  view  also  shows  the  way  in  which  the  bearings 
of  the  shafts  A  and  B  are  made  water-tight  by  the  use  of  the  cup 
packings  a'  and  b' '.  The  shafts  are  incased  in  brass  tubing  a  b  to  prevent 
corrosion. 

The  safety  device  attached  to  the  main  valve  in  Fig.  250  is  clearly 
shown  in  Fig.  252;  it  consists  of  the  small  pipe  connection  a,  and  its 
operation  is  as  follows :  Suppose  the  car  is  running  upward ;  when  it 
reaches  the  upper  floor  the  top  stop  valve  Z  will  close,  and  at  the  same 


306  HYDRAULIC  ELEVATORS 

time  the  main  valve  piston  T'  will  move  to  the  left,  thereby  locking 
pressure  water  in  the  space  S'  between  the  main  valve  and  the  stop  valve. 
This  pressure  will  force  the  cup  packings  of  the  stop  valve  Z  out  so  as 
to  develop  possibly  sufficient  friction  to  prevent  lever  V  and  the  weight 
of  sheave  V  from  shifting  the  valve  to  the  open  position  when  the  car 
starts  on  the  down  trip.  When  the  pipe  a  is  provided  this  cannot  happen 
because  in  order  to  run  the  car  down  the  main  valve  has  to  be  moved 
to  the  left  so  that  the  piston  R  may  be  carried  beyond  the  port  and  thus 
open  communication  between  E  and  E'.  As  soon  as  the  main  valve 
moves  far  enough  for  the  piston  T  to  pass  to  the  left  of  the  inlet  of 
pipe  a,  the  pressure  in  Sr  drops  to  equality  with  that  in  E'  and  then  the 
friction  of  the  cup  packings  of  valve  Z  is  so  reduced  that  the  valve 
cannot  stick.  It  might  be  said  that  this  same  result  could  be  accomplished 
by  putting  additional  weight  on  the  lever  V.,  but  this  would  increase  the 
tension  on  the  operating  rope,  which  is  objectionable. 


CHAPTER  XLII 

PRACTICAL  INSTRUCTIONS  IN  THE  CARE  AND  MANAGE- 
MENT OF  THE  "STANDARD"  PLUNGER  ELEVATOR; 
ESSENTIAL  FEATURES  TO  LOOK  OUT  FOR 

Whenever  it  is  desired  to  take  out  the  main  valve  of  the  Standard 
plunger  elevator,  it  can  be  removed  through  the  back  end  of  the  valve 
cylinder.  Before  it  can  be  drawn  out,  however,  the  rack  at  the  end  that 
rotates  the  pinion  of  the  pilot  valve  must  be  thrown  out  of  gear.  To 
do  this  all  that  is  necessary  is  to  remove  the  hood  in  front  of  the  pilot 
valve,  into  which  the  rack  runs,  and  then  the  shoe  that  holds  the  rack 
and  pinion  in  mesh  can  also  be  removed  and  the  rack  can  be  pushed  to 
one  side  so  as  to  clear  the  teeth  of  the  pinion.  When  this  is  done  the 
valve  can  be  drawn  out  of  the  back  end  of  the  valve  cylinder  without 
difficulty. 

To  remove  the  automatic  stop  valve  the  cylinder  head  must  be 
removed,  and  also  the  bonnet  under  the  center.  The  cranks  that  operate 
the  automatic  stop  valves  are  fastened  to  the  shafts  on  which  the  operating 
levers  are  mounted  by  means  of  caps,  and  the  screws  that  hold  these 
caps  can  be  reached  when  the  bonnet  is  removed.  If  the  cap  is  taken 
off  the  crank  can  be  pushed  upward  and  can  be  drawn  out,  together 
with  the  valve,  through  the  end  of  the  valve  cylinder;  all  of  which  can 
be  readily  understood  upon  examining  the  valve  drawing,  Fig.  234.  The 
cranks  are  keyed  to  the  shafts,  to  prevent  them  from  turning,  and  in 
putting  the  valve  back  care  must  be  taken  that  the  key  is  returned  to 
position  and  the  screws  tightened  up  as  much  as  they  were  before,  so 
that  there  may  be  no  danger  of  working  the  parts  loose  thereafter. 

PILOT   VALVE    REMOVAL   AND   ADJUSTMENT. 

The  pilot  valve,  body  and  all,  can  be  removed  by  taking  off  the  end 
hood  the  same  as  for  throwing  the  rack  out  of  gear,  as  explained  above. 
When  this  hood  is  removed,  the  bolts  that  hold  the  pilot-valve  body 
can  be  reached  and  taken  out  and  then  the  valve  can  be  removed, 
together  with  the  shaft  that  carries  the  pinion  and  the  cams  that  prevent 
too  rapid  reversal  of  the  elevator  motion.  A  side  view  of  all  these  parts 
is  given  in  Fig.  254,  which  is  a  vertical  section.  This  drawing  does  not 
show  the  means  by  which  the  valve  body  is  fastened  to  the  end  casting 

307 


308 


HYDRAULIC  ELEVATORS 


of  the  main  valve  body ;  these  consist  of  lugs  that  spread  out  on  each  side 
of  the  shaft  L"  at  the  top  and  bottom,  opposite  the  bearings  through 
which  the  shaft  slides.  A  view  of  the  valve  body  at  right  angles  to 
Fig.  254  would  show  these  lugs,  on  opposite  sides  of  the  parts  E  and  F. 


FIG.  254 

To  remove  the  valve  alone,  all  that  is  necessary  is  to  take  off  the  con- 
necting arm  D  and  the  lower  cap  C ;  then  the  valve  can  be  drawn  out 
through  the  lower  end. 

It  can  be  seen  that  no  provision  is  made  for  adjusting  the  position  of 
the  pilot-valve  cup  packings,  nor  for  adjusting  the  cams  a,  b,  a'  and  b'. 
Adjustment  of  the  position  of  the  cup  packings  would  only  serve  to  vary 
the  lap  of  the  valve,  and  such  adjustment  is  not  only  not  necessary  but 


CARE  AND  MANAGEMENT  309 

not  advisable,  because  the  manufacturers  know  better  than  any  one  else 
what  the  adjustment  should  be,  and  they  make  the  valve  of  proper  pro- 
portions. Increasing  the  depth  of  the  cups  will  not  have  any  effect  on 
the  lap  of  the  valve,  because  they  enter  their  seats  back  end  first  and 
make  a  joint  after  entering  a  certain  distance,  independent  of  the  depth 
of  the  cup.  Under  certain  conditions,  if  the  edge  of  the  cup  projects 
beyond  the  end  of  the  cylinder,  water  may  force  its  way  between  it  and 
the  cylinder  and  thus  leak  through.  This  is  not  likely  to  occur,  but  as 
it  may,  it  is  wise  to  use  cups  of  the  proper  depth,  and  no  deeper.  The 
cams  require  no  adjustment,  because  all  they  are  intended  for  is  to 
prevent  moving  the  lever  any  farther,  in  stopping,  than  it  was  moved  in 
starting;  and  if  once  made  of  the  proper  dimensions  to  accomplish  this 
result,  they  will  always  do  so. 

The  only  adjustment  provided  in  the  pilot  valve  is  in  the  ports 
through  the  sleeves  A,  A'  at  the  ends  of  the  valve,  and  the  similar 
adjustment  on  the  side  ports,  which  was  fully  explained  in  the  article 
describing  this  apparatus.  If  in  the  course  of  time  the  water  flowing 
through  these  port  holes  enlarges  them  so  as  to  cause  the  main  valve  to 
close  too  rapidly  in  stopping,  the  proper  adjustment  can  be  obtained  by 
running  in  the  adjusting  plugs  a  trifle.  It  may  be  found  in  making 
such  changes  that  the  car  speeds  up  too  fast  in  starting  when  the  valve  is 
partly  opened  in  order  to  run  at  a  slow  speed.  If  this  should  be  the  case, 
the  acceleration  can  be  reduced  by  screwing  in  farther  the  plug  opposite 
the  port  hole  in  the  inner  end  of  the  sleeve  A,  and  if  after  doing  this 
the  car  does  not  get  under  headway  fast  enough  when  the  valve  is  fully 
opened,  the  acceleration  can  be  increased  by  drawing  out  one  of  the  other 
adjusting  plugs.  In  making  these  adjustments  it  should  be  remembered 
that  a  very  small  difference  in  the  opening  of  the  ports  will  make  a 
decided  difference  in  the  rapidity  with  which  the  elevator  will  get  under 
way ;  hence,  the  position  of  the  plugs  should  be  changed  only  a  little  at  a 
time.  In  the  type  of  valve  shown  in  Fig.  234  the  main  valve  is  moved 
to  the  right  to  cause  the  elevator  to  start  upward ;  it  is  also  moved  to 
the  right  to  stop  the  elevator  on  downward  trips.  Therefore,  if  the  flow 
of  water  through  the  ports  of  the  top  sleeve  A  is  decreased,  the  effect 
will  be  to  reduce  the  acceleration  in  starting  on  up  trips,  and  to  prolong 
the  stopping  on  down  trips.  To  stop  going  up  and  to  start  going  down 
the  main  valve  must  be  moved  to  the  left;  hence,  if  the  adjusting 
plugs  opposite  the  ports  in  the  lower  sleeve  A  are  run  in,  the  up  stops 
and  the  downward  starts  will  be  made  slower,  and  vice  ver^sa. 

If  the  elevator  is  arranged  so  that  the  cylinder  discharges  into  an 
open  tank  located  on  a  level  with  the  main  valve,  there  will  be  no  back 
pressure  to  force  the  water  into  the  cylinder  through  the  bypass  connec- 


310  HYDRAULIC  ELEVATORS 

tion,  and  the  adjustment  of  the  velocity  of  motion  of  the  main  valve 
must  therefore  be  made  so  as  to  reduce  the  velocity  enough  to  prevent 
jumping  the  plunger  off  the  water  in  the  cylinder  when  the  car  is  brought 
from  its  maximum  speed  to  a  stop.  If,  however,  the  water  in  the 
cylinder  is  discharged  into  an  elevated  tank,  or  into  a  pressure  tank,  the 
valve  is  adjusted  with  reference  to  starting  on  the  downward  trips,  so 
that  the  car  may  not  move  so  rapidly  as  to  produce  an  unpleasant  sensa- 
tion. Therefore,  it  will  be  seen  that  the  adjustment  of  the  plugs  at  the 
lower  end  of  the  pilot  valve,  opposite  sleeve  A,  must  be  made  with 
reference  to  the  rapidity  of  stopping  on  the  upward  trips,  with  one 
method  of  piping,  and  with  reference  to  starting  on  the  downward  trips 
with  the  other  method.  * 

The  adjustment  of  the  plugs  opposite  the  sleeve  A  at  the  top  of  the 
pilot  valve  is  made  with  reference  to  the  rapidity  of  starting  on  the 
upward  trips,  and  stopping  on  downward  trips.  There  is  -little  danger  of 
starting  too  rapidly,  because  the  water  flowing  into  the  cylinder  has  to 
lift  the  load,  and  it  cannot  very  well  get  it  under  headway  so  rapidly  as 
to  produce  an  unpleasant  sensation,  unless  the  lifting  capacity  of  the 
plunger  is  excessive,  and  the  load  in  the  car  is  light.  In  stopping  on 
the  downward  trips,  however,  the  reduction  of  speed  can  be  so  rapid  as 
to  greatly  increase  the  tendency  to  buckle  the  plunger,  hence  the  adjust- 
ment of  the  plugs  at  the  top  of  the  pilot  valve  should  be  made  with 
reference  to  the  rate  of  retardation  of  speed  in  stopping  on  the  down 
trips,  and  this  adjustment  will  be  found  satisfactory  for  the  starting  on 
upward  trips. 

In  the  .valve  shown  in  Fig.  233  the  movement  of  the  main  valve  is 
the  reverse  of  that  above  explained,  that  is,  the  valve  moves  to  the  left 
to  start  on  the  upward  trip,  instead  of  to  the  right,  hence  the  top 
adjusting  plugs  are  used  to  do  just  what  the  bottom  ones  do  in  Fig.  234. 

THE  PACKINGS. 

All  the  packings  used  in  the  valves  of  the  Standard  plunger  elevators 
are  leather  cups,  as  can  be  seen  by  looking  at  the  various  drawings  we 
have  presented.  These  packings  are  replaced  in  the  same  manner  as  in 
the  elevators  of  other  makes  previously  explained,  and  require  no  further 
explanation  here.  The  stuffing-box  at  the  top  of  the  plunger  cylinder  is 
packed  either  with  hemp  or  any  good  soft  packing,  or  with  a  specially 
constructed  double  cup  leather  packing.  The  cross-section  of  this  packing 
is  shown  in  Fig.  255.  The  packing  is  made  in  two  parts,  A  and  B,  both 
of  leather.  These  two  parts  are  cut  on  one  side,  so  that  they  may  be 
slipped  over  the  plunger  from  the  side,  and  they  are  placed  in  the  stuffing- 
box  so  that  the  joints  are  on  opposite  sides  of  the  diameter. 


CARE  AND  MANAGEMENT 


To  keep  any  hydraulic  elevator  in  perfect  running  order  it  is  necessary 
that  all  the  packings  be  kept  tight;  if  they  are  not,  the  car  will  not 
remain  stationary  when  stopped  at  a  floor,  but  will  move  gradually 
either  up  or  down,  according  to  where  the  leak  is  located.  In  plunger 
elevators,  if  the  stuffing-box  at  the  top  of  the  cylinder  leaks  the  car  will 
settle  when  standing  at  a  floor.  It  is  an  easy  matter  to  determine 
whether  the  cylinder  stuffing-box  leaks  or  not,  for  if  it  does  the  water 
can  be  seen  trickling  over  the  top  of  the  stuffing-box  gland.  If  there  is 
no  leak  at  this  point,  then  the  trouble  will  be  found  in  the  main  valve, 
which  will  permit  water  to  flow  through  to  the  discharge  pipe ;  hence, 
the  packing  in  the  piston  that  shuts  off  the  discharge  must  be  renewed. 


-B 


FIG.  255 

If  the  car  creeps  upward  after  being  brought  to  a  stop  it  indicates  that 
the  cup  packing  in  the  valve  piston  that  closes  the  supply  ports  is  leaky. 
Sometimes  the  elevator,  after  being  brought  to  a  standstill,  creeps  up  a 
short  distance  and  then  creeps  back,  and  continues  this  alternating  motion 
indefinitely.  This  indicates  that  the  pilot  valve  is  defective,  and  it  is  an 
occurrence  that  can  take  place  with  any  type  of  hydraulic  elevator. 

In  addition  to  keeping  all  the  packings  in  good  condition  it  is  neces- 
sary that  the  running  gear  of  the  valves  be  not  allowed  to  get  out  of 
adjustment.  The  rope  that  moves  the  pilot  valve  and  those  that  operate 
the  automatic  stop  valves  must  be  examined  frequently  to  see  that  they 
are  in  good  condition  and  their  fastenings  tight,  particularly  as  to  the 
stop- valve  ropes,  because  these  valves  are  safety  devices. 

With  the  Standard  plunger-elevator  system  in  which  the  discharge 
tank  is  closed  and  a  pressure  is  maintained  therein,  it  is  necessary  that 
the  pressure  be  kept  up  to  the  proper  point  to  obtain  the  best  results. 
The  pressure  is  required  to  cause  the  water  to  follow  up  the  plunger 


312  HYDRAULIC  ELEVATORS 

when  the  valve  is  closed  suddenly  in  making  a  stop  on  the  up  trips.  If 
the  pressure  is  permitted  to  drop  the  plunger  may  be  drawn  away  from 
the  water  in  the  cylinder,  with  the  results  already  explained.  There  is 
no  danger  of  getting  the  pressure  too  high,  as  this  is  limited  by  the 
hight  of  the  inverted  goose  neck  provided  for  that  purpose.  It  is  not 
desirable,  however,  to  permit  the  pressure  to  rise  above  the  proper  point, 
because  too  much  water  will  be  forced  out  through  the  goose  neck,  and 
this  will  have  to  be  replaced  by  water  drawn  from  an  outside  source, 
which  generally  will  be  at  a  lower  pressure;  hence  it  will  represent  just 
so  much  power  thrown  away.  It  is  also  necessary  that  the  supply  of  air 
in  the  discharge  tank  be  well  maintained ;  otherwise,  the  pressure  will 
vary  too  much  when  water  is  drawn  from  the  tank  or  discharged  into  it. 
Whenever  the  construction  of  the  building  permits,  the  pressure  in  the 
discharge  tank  is  obtained  by  locating  it  at  the  proper  elevation,  as  this 
is  decidedly  the  best  arrangement,  as  the  pressure  then  cannot  vary. 
With  an  elevated  tank  all  that  is  necessary  is  to  keep  the  water  at  the 
proper  level  so  that  the  pipe  running  down  to  the  cylinder  may  always 
be  far  enough  below  the  surface  not  to  draw  in  air, 


CHAPTER  XLIII 

HAND-ROPE  CONTROL  FOR  FREIGHT  ELEVATORS ;  PUMPS 

AND  CONNECTIONS  USED  WITH  "SAFE  LIFTERS"; 

LOCKING  DEVICE  FOR  PLUNGER  ELEVATORS; 

HAND-ROPE  CONTROL 

Regarding  plunger  elevators  controlled  by  a  simple  hand  rope  and 
valve  there  is  little  information  to  give  except  in  the  matter  of  manipu- 
lating the  rope.  The  valve  proper  is  made  substantially  the  same  as  this 
type  of  valve  for  other  forms  of  hydraulic  elevator,  but  the  distance 
through  which  the  hand  rope  is  pulled  to  make  a  start  or  stop  is  slightly 
greater  for  the  high-speed  cars  than  it  is  with  cable  elevators.  The 
reason  why  the  hand  rope  has  to  be  moved  through  so  great  a  distance 
is  not,  as  may  be  supposed,  that  the  effort  necessary  to  move  it  may 
be  reduced,  but  that  the  valve  may  not  be  closed  too  rapidly  by  the 
movement  of  the  elevator  car  as  it  approaches  the  upper  or  lower 
landing.  In  slow-running  elevators  the  stretch  of  the  hand  rope  upon 
which  the  stop  balls  are  fastened  passes  through  the  car,  and  by 
manipulating  this  rope  the  elevator  is  controlled.  In  high-speed  cars 
both  stretches  of  the  hand  rope  pass  through  the  car  and  both  are 
handled  to  control  the  movement.  The  advantage  of  this  latter  arrange- 
ment will  be  made  clear  by  reference  to  Fig.  256,  which  is  a  vertical 
elevation  of  a  fast-running  plunger  freight  elevator.  The  stretch  B  of 
the  hand  rope  is  the  one  ordinarily  used  to  operate  the  car,  and  this  is 
pulled  down  to  cause  the  car  to  ascend,  and  pulled  up  to  cause  the 
car  to  descend.  It  will  be  obvious,  however,  that  if  the  rope  has 
to  be  pulled  down,  say,  15  feet  to  make  the  car  run  upward  at 
full  speed,  the  operator  would  have  a  hard  time  doing  it  unless 
he  were  extremely  quick  in  his  movements;  the  first  pull  of  the 
rope  might  not  draw  it  down  more  than  3  or  4  feet,  which  would  be 
sufficient  to  set  the  car  in  motion  at  a  fair  rate  of  speed,  but  not  at  the 
maximum,  and  the  operator  would  have  great  difficulty  in  pulling  the 
rope  down  farther  because  the  car  would  be  running  upward.  By 
starting -the  car  by  the  aid  of  the  stretch  C  of  the  hand  rope  the  case 
will  be  very  different,  because  this  side  must  be  pulled  upward  to  make 
the  car  run  upward;  therefore,  all  that  is  necessary  is  to  give  the 
stretch  C  a  slight  upward  pull,  and  then  hold  on  to  it  until  the  car 

313 


FIG.  256 
FREIGHT    PLUNGER    ELEVATOR 


314 


HAND-ROPE  CONTROL  315 

/  . 

attains  full  speed.  To  prevent  moving  the  rope  too  far  a  stop  is  fastened 
on  the  stretch  C,  and  this  runs  between  two  stationary  stops  set  at  the 
proper  points ;  hence,  if  in  starting  the  operator  desires  to  run  up  at  full 
speed  all  he  has  to  do  is  to  pull  the  stretch  C  up  far  enough  to  open  the 
valve  and  then  hold  it  until  the  stop  on  the  rope  strikes  the  stationary  stop. 
To  make  a  stop  at  any  floor  going  downward  the  operation  is  reversed, 
that  is,  in  starting,  the  stretch  C  is  pulled  down  slightly  and  held  until 
the  desired  speed  is  obtained,  and  to  make  a  stop  the  stretch  is  grasped 
and  held,  just  as  in  stopping  on  the  upward  trip.  The  stationary  stops 
that  limit  the  movement  of  the  rope  when  the  stretch  C  is  held  are  set 
apart  a  distance  equal  to  the  combined  distances  through  which  the  stop 
balls  on  the  rope  B  move  at  the  top  and  bottom  of  the  well  to  stop  the 
car.  Thus  if  the  top  ball  moves  15  feet  and  the  bottom  ball  10  feet, 
the  stationary  stops  that  limit  the  movement  of  the  stretch  C  will  be 
set  25  feet  apart,  and  the  stop  ball  qn  C  will  be  15  feet  below  the  upper 
stationary  stop  when  the  car  is  standing  at  any  floor. 

"SAFE  LIFTERS." 

In  all  large  buildings  one  of  the  elevators  has  to  be  designed  to  lift 
extra  heavy  loads,  ranging  from  about  6000  to  10,000  or  12,000  pounds, 
according  to  the  size  of  the  building  or  the  character  of  the  business 
done  by  the  occupants.  This  elevator  is  generally  called  a  safe  lifter,  as 
the  heaviest  loads  it  carries  are  usually  safes.  If  it  were  intended  to 
carry  such  loads  all  the  time  it  would  be  arranged  precisely  the  same  as 
the  other  elevators  in  the  building  except  that  the.  cylinder  and  the  main 
valve  would  be  made  as  much  larger  as  might  be  necessary  to  lift  the 
heavier  load.  But  this  elevator  is  only  called  upon  occasionally  to  lift 
extra-heavy  loads,  and  it  is  therefore  made  of  the  same  normal  lifting 
capacity  as  the  other  elevators,  but  with  parts  sufficiently  larger  than 
normal  to  give  it  the  proper  strength  to  carry  the  extra  load ;  the  increased 
lifting  power  is  obtained  by  increasing  the  pressure  of  the  water  that 
operates  it,  when  used  to  lift  heavy  loads.  The  common  practice  with 
all  types  of  hydraulic  elevator  used  for  safe  lifters  is  to  provide  a  small 
high-pressure  pump  that  is  capable  of  developing  the  pressure  required 
to  lift  the  load,  and  this  is  connected  directly  with  the  lifting  cylinder,  so 
that  when  a  heavy  load  is  handled,  all  the  parts  of  the  elevator  excepting 
the  lifting  cylinder  and  the  pipes  directly  connecting  with  it  are  cut  out 
of  service,  and  are  not  subjected  to  the  high  pressure.  The  way  in 
which  the  Standard  plunger  elevators  are  arranged  when  used  as  safe 
lifters  is  illustrated  in  Fig.  257,  which  shows  an  elevation  and  a  plan 
view.  In  the  elevation  the  high-pressure  pump,  used  to  lift  the  heavy 
load,  is  moved  some  distance  to  the  right,  so  as  to  bring  it  out  from 
behind  the  main  valve  and  the  automatic  stop  valves.  The  true  position 


HYDRAULIC  ELEVATORS 


of  the  pump  and  the  pipe  connections  between  it  and  the  lifting  cylinder 
is  shown  in  the  plan  view.  The  high-pressure  suction  pipe  taps  into  the 
main  discharge  at  the  bend  D,  and  the  delivery  pipe  from  the  high- 
pressure  pump  connects  with  pipe  A  at  the  upper  end.  At  the  places 


FIG.  257 

PIPING   PLAN    FOR    STANDARD    PLUNGER   ELEVATOR   ARRANGED    FOR    SAFE 

LIFTING 

marked  V1,  V2,  Vz  and  V*  are  located  hand  valves  for  the  purpose  of 
disconnecting  the  main  valves  from  the  cylinder  and  from  the  tanks. 
The  valves  V5,  F8,  V  and  F8  are  located  in  the  piping  of  the  high- 
pressure  pump,  and  are  for  the  purpose  of  operating  the  elevator  when 


HAND-ROPE  CONTROL 


317 


used  to  lift  extra-heavy  loads.  When  such  a  load  is  to  be  lifted, 
valves  V2,  V*  and  F4  are  closed  to  prevent  high-pressure  water  from 
reaching  the  main  operating  valves.  The  high-pressure  pump  is  started 
when  the  load  is  to  be  raised,  and  valves  F5  and  V*  are  opened ;  then 
water  is  drawn  into  the  high-pressure  pump  through  the  high-pressure 
suction  from  the  main  discharge  pipe ;  and  from  the  high-pressure  delivery 
pipe  it  passes  through  valve  F5,  and  thence  into  pipe  B  through  pipe  A 
to  the  lifting  cylinder,  forcing  the  plunger  and  car  upward. 

As  long  as   the  pump   is   kept  running  the   elevator  will   rise,   and 


i — 


FIG.  259 


FIG.  258 

when  the  stopping  place  is  reached,  the  pump  is  stopped.  As  the 
movement  of  the  car  is  controlled  entirely  by  the  running  of  the  pump 
and  the  manipulation  of  the  valves  F5,  F6,  F7  and  F8,  communication 
of  some  sort  must  be  established  between  the  car  operator  and  the  man 
at  the  pump.  This  is  generally  done  by  means  of  electric  bells  or  a 
telephone.  With  this  method  of  operating  the  car,  accurate  stops  at  the 
floors  of  the  building  cannot  be  made  at  the  first  trial,  so  that  the 
general  practice  is  to  stop  the  car  a  short  distance  above  the  floor,  and 
then  to  lower  it  slowly  to  the  proper  position  by  opening  the  valve  F7 
in  the  pipe  B'  so  as  to  permit  water  to  escape  slowly  from  the  cylinder. 
If  the  elevator  is  to  be  run  down  any  considerable  distance,  as  for 
example  when  it  is  lowered  to  the  ground  floor  after  receiving  its  load, 
the  valve  F6  is  opened,  allowing  the  water  to  escape  faster  from  the 
lifting  cylinder.  When  the  car  approaches  near  enough  to  the  lower 
floor,  valve  F6  is  closed  and  the  car  descends  the  remaining  distance 
at  a  greatly  reduced  speed,  as  the  water  can  escape  only  through  the 


HYDRAULIC  ELEVATORS 


small  pipe  B'  and  the  valve  V1.  By  properly  manipulating  this  latter 
valve  the  descent  of  the  car  can  be  made  as  slow  as  desired.  When 
the  car  is  being  lowered  the  high-pressure  pump  is  not  operated. 

When  an  elevator  is  used  to  raise  or  lower  a  heavy  load  that  requires 
some  time  to  place  upon  the  car,  it  is  not  advisable  to  depend  upon  the 
lifting  cylinder  to  hold  the  car  in  position  while  the  loading  is  going  on, 
because  during  this  time  the  car  might  settle  enough  to  cause  some 


FIG.  260 

trouble,  if  not  to  do  actual  damage.  Owing  to  this  fact  it  is  customary 
to  provide  an  elevator  used  as  a  safe  lifter  with  a  locking  device  at 
each  floor  that  will  hold  the  car  immovable  while  it  is  being  loaded. 
This  device  is  thrown  into  action  after  the  car  has  been  run  up  a  short 
distance  above  the  floor,  and  then  by  opening  the  valve  V1 ',  as  already 
explained,  the  car  is  permitted  to  settle  gradually  upon  the  locking  device. 
When  the  load  is  in  position  the  first  thing  to  do  is  to  run  the  car  up 
far  enough  to  free  the  locking  device,  then  this  is  drawn  out  of  the 
way  and  the  car  is  started  for  its  destination. 

LOCKING  DEVICE   FOR  PLUNGER  ELEVATORS. 

The  type  of  locking  device  used  with  the  Standard  plunger  elevators 
is  shown  in  Figs.  258  and  259,  the  former  giving  a  plan  view  and  a 
front  view  of  the  apparatus  and  the  latter  a  side  view.  At  every  floor 
of  the  building  strong  supports  A,  A'  are  secured  in  the  proper  position 


HAND-ROPE  CONTROL  319 

upon  the  guide  rails  T,  T,  to  hold  the  car  level  with  the  floor.  Under  the 
car  are  secured  strong  bars  B,  B'  which  are  pushed  out  over  the  supports 
A,  A'  by  means  of  levers  connected  with  a  vertical  shaft  F  located  in 
the  car  floor  at  one  corner  and  so  arranged  that  it  can  be  turned  by  a 
socket  wrench.  On  the  lower  end  of  the  shaft  is  fastened  a  crank  E;  a 
rod  D  links  the  crank  to  a  lever  C,  which  is  pivoted  at  G  and  at  its  end 
engages  with  a  stud  G'  mounted  on  the  lock  bar  B.  A  connecting  bar 
D'  is  connected  with  the  lever  C  by  a  stud  G",  and  through  this  con- 
nection any  movement  of  C  imparts  motion  to  the  lever  C  which  is 
pivoted  at  H  and  moves  the  lock  bar  B'  through  the  stud  connection  //'. 
If  the  shaft  F  is  turned  counter  clockwise,  the  lock  bars  B,  B'  will  be 
moved  outward  over  the  stationary  supports  A,  A'.  In  Fig.  258  the  lock 
bars  B,  B'  are  shown  very  close  to  the  supporting  pieces  A,  A',  but  when 
they  are  in  their  normal  position  they  are  drawn  in  far  enough  to  prevent 
accidental  striking  of  the  stationary  supports.  The  position  of  the  levers 

C,  C'  is  such  that  the  shaft  F  can  be  rotated  clockwise  as  well  as  in  the 
opposite  direction,  and  then  the  bars.  B,  B'  will  be  drawn  in  toward  the 
center  of  the  car. 

When  a  plunger  elevator  is  used  to  lift  safes  the  compression  stress 
on  the  plunger  is  greatly  increased,  as  no  additional  counterbalance  is 
provided  to  offset  the  weight.  This  extra  stress  is  not  serious  in  elevators 
of  moderate  rise,  but  when  the  rise  is  fairly  great,  say  between  200  and 
300  feet,  it  is  necessary  to  provide  a  stiffener  to  reinforce  the  plunger 
and  avoid  liability  of  buckling  it.  The  stiffener  used  with  the  Standard 
plunger  elevators  is  shown  in  Fig.  260,  which  gives  a  side  elevation  and 
a  plan  view.  It  consists  of  a  frame  B  carrying  at  the  center  a  guide 
through  which  the  plunger  P  slides,  and  at  its  ends  guide  wheels  B',  B' 
that  run  on  the  elevator  guides  T,  T.  The  frame  also  carries  two  sheaves 

D,  D'  under  which  pass  two  ropes  E,  E',  fastened  at  one  end  to  the 
under  side  of  the  car  and  at  the  other  end  to  the  beams  at  the  top  of 
the  elevator  well.    As  the  elevator  runs  upward,  the  rope  ends  attached 
to  it  are  drawn  upward,  of  course,  and  pulling  the  frame  B  upward  just 
one-half  as  fast  as  the  car  moves,  so  that  at  all  times  the  frame  will 
be  at  a  point  midway  between  the  bottom  of  the  well  and  the  car,  and 
will  brace  the  plunger  at  the  central  point  of  its  exposed  length. 

The  plungers  of  these  elevators  are  made  as  nearly  water-tight  as 
practicable,  but  they  are  liable  to  be  leaky  sometimes.  If  a  plunger 
leaks,  the  effect  will  be  that  the  load  to  be  raised  will  be  increased  by 
whatever  the  water  in  the  plunger  may  weigh.  In  extreme  cases,  in  very 
high  buildings,  the  accumulation  of  water  in  the  plunger  may  be  sufficient 
to  prevent  the  elevator  from  lifting  its  maximum  load.  If  the  plunger 
leaks,  it  is  not  an  easy  matter  to  make  it  tight,  but  it  is  a  very  simple 


320  HYDRAULIC  ELEVATORS 

thing  to  remove  the  water,  and  this  should  be  done.  The  best  way  to 
do  it  is  to  drill  a  hole  about  *4  mcn  m  diameter  in  the  lower  section  of 
pipe,  just  above  the  end  casting,  say  2  feet  above  the  lower  end  of  the 
pipe,  and  draining  the  water  out.  After  the  water  is  out  the  hole  must 
be  plugged  up.  This  is  easily  done  by  tapping  the  hole  and  screwing  in 
a  brass  plug,  which  should  be  filed  off  flush  with  the  plunger  surface  and 
smooth. 


INDEX 


INDEX 


Accidents,  105. 

Accumulators,  construction  of,  205. 

for  high  pressure  machines,  190. 

on  Otis  elevators,  205. 

reserve,  231. 
Air,  chamber,  auxiliary,  228. 

check  valve  on  outlet  feed  of,  229. 

effect  in  the  lifting  cylinder,  90. 
Alinement  of  cylinders,  116. 
Anchoring  of  cylinders,  114,  168. 
Arrangements,  diagram  of,  for  high  pres- 
sure elevators,  230. 
Automatic  stop-valve,  56. 

with  accumulators,  228. 

adjustment  of,  155. 

cleaning  and  inspection  of,  179,  221. 

construction  of,  Otis  type,  273. 

on  Crane  elevators,  159. 

danger  in  changing  adjustment  of, 
224. 

derangement  of,  156. 

electrical  control  of,  75. 

non-interfering,  75. 

on  Morse  and  Williams,  176. 

operation  of,  136,  177. 

on  Otis  high  pressure  machines,  212, 
291. 

on  plunger  elevators,  240,  252. 

on  "  Standard  "  plunger  elevators,  304. 

for  stopping  cars  at  top  and  bottom 
landings,  100. 

troubles  of,  104. 

Buffer,  rubber,  for  car  and  for  counter- 
balances, 242. 

construction  of  on  "Standard"  ele- 
vators, 302.  * 

on  travelling  sheaves,  138. 

Cables,  electric,  care  of,  128. 
Check-valve,  in  outlet  from  air  cham- 
ber, 229. 
Control,  52. 

by  magnetically  operated  valve,  66, 

68,  70,  73. 
by  pilot  valve,  52. 


Controller,  floor,  76,  124. 
Counter  balancing,  11. 

independent,  11. 

for  the  lifting  ropes,  25. 

in  plunger  elevators,  19,  265. 
Cup  packing,   for  high  pressure  eleva- 
tors, 188. 

Cushion,  spring,  chamber,  232. 
Cylinder,  alinement  of,  116. 

anchoring  of,  114. 

care  of,  163. 

construction   of,   139,   240;    for   high 
pressure  machines,  194. 

Crane,  cylinder,  packing  of,  159. 

friction  in,  121. 

lubrication  of,  121. 

Differential  valves,  98. 
Double  piston  rods,  33. 
Double  power  systems,  30,  79. 

Otis  double  power  elevator,  79. 
Drain  pipes,  inspection  of,  127. 
Drip-pans,  173. 

Electrical,  device  for  controlling  the 
pump,  210. 

features  of  hydraulic  elevators,  123. 

care  of,  parts,  210. 
Equal  pressure,  device  to  obtain,  9. 

Floor    controller,    non-interfering,     76, 

124. 
Freight  elevator,  simple  type,  the  Otis, 

257. 

Gear  ratio  of  elevator  machines,  how  to 

determine,  6. 
Gravity  system,  30. 
Guide  shoes,  64. 

Hand-rope  control  for  plunger  eleva- 
tors, 313. 

Hand-wheel  used  in  place  of  pilot 
valve  in  Morse  and  Williams  ele- 
vator, 184,  202. 

Heavy  service  elevators,  232. 
operation  of,  233. 


323 


INDEX 


High  pressure  elevators,  14. 

hydraulic  elevators,  187. 

use  of  accumulators  with,  205. 
Horizontal  cylinder  machines,  21. 

compared  with  vertical,  23. 

description  of  "pushing"  and  "pull- 
ing" type,  131. 

operation  of  "pulling"  type,  142. 

operation  of  "pushing"  type,  133.- 

operation  of  Whittier,  142. 

operation  of  Morse  and  Williams,  147- 

Lifting-cylinder,  design  of,  292. 
Locking   device   for   plunger   elevators, 

318. 

Low  pressure  system,  17. 
Lower  casting,  design  of,  for  plunger, 

295. 

Lubricating,  the  cylinder,  121;  of  a  hori- 
zontal machine,  182. 
sheaves  in  horizontal  machine,  170. 
sheaves,  overhead,  173. 
slide  on  which  crossheads  run,  183. 


Magnetic  control  of  valve,  66,  68,  70, 

202. 
Magnets,  care  of,  126. 

for  high  pressure  elevators,  204. 

removing,  128. 
Main  valves   and   pilot-control  valves, 

arrangement  of,  254. 

operation  of,  135. 
Morse  and  Williams,  147,  154,  176. 

One-to-one  gearing  for  elevators,  3. 
Operating  valve,  construction  of,  261. 

main,  with  Otis  plunger  machines,  244 
Otis  elevators,  30. 

double  power  vertical,  79. 

automatic  stop-valves  on,  271. 

ball  and  socket  bearing  for   sheaves 
on,  172. 

main  operating  valve  on,  244. 

governor  on,  38. 

plunger  type,  280. 

running  rope  system  on,  85. 

simple  type  of,   for  carrying  freight, 
using  hand  or  rope  control,  257. 

travelling  sheave  frames  on,  113. 

vertical,  209. 


Packing,  for  accumulator,  225. 

for    cylinder    on    high    pressure    ma- 
chines, 226. 

for  piston,  93. 

for  main  and  cylinder  pistons  of  crane 
elevator,  159. 

for  Morse  and  Williams  piston,   150, 
181. 

for    plunger    on    high    pressure    ma- 
chines, 226,  268. 

how   to    renew    packing    for    plunger 
on,  267. 

for  "Standard"  piston,  307. 

for  stuffing  boxes,  96. 

for  stop-valves,  101. 

for  valves,  96. 

for  valves,  high  pressure,  225. 

for  Whittier  piston,  169. 
Passenger  elevator,  construction  of,  238. 

"Standard",  300. 

management  of,  307. 

operation  of,  302. 
Pilot  valve,  46,  47. 

adjustment  of,  for  speed  regulation, 
129,  246,  286,  307. 

auxiliary,  to  ease  stopping  of  plunger, 
245,  248. 

control  of,  52. 

location  of,  how  to  decide  upon,  129. 

magnetic,  68. 

operation  of,  135,  286. 

on  high  pressure  vertical  machines, 
201. 

secondary,  70. 

removal  of,  for  adjustment,  on  "  Stan- 
dard   elevators,    307;   on  Whittier 
elevators,  144. 
Piping  connections,  297. 
Pistons,  43. 

air  as  a  cause  of  "settling"  of,  91. 

on  Morse  and  Williams  elevators,  150. 

packing  of ,  92.  * 

packing  of,  Crane  type,  159. 

weighting,  the  reason  for,  120. 
Plunger  elevators,  18. 

construction  of  plungers  for,  238,  240, 
242. 

high  pressure,  194. 

described,  236. 

diameters  of  plunger,  usual,  on,  265. 

hand -rope  control  for,  313. 


324 


INDEX 


Plunger  elevators,  locking  device  for, 
318. 

management  of,  307. 

operation  of,  302. 

pilot  valves  on,  245,  248;  the  adjust- 
ment and  removal  of,  on,  307;  the 
packing  of,  on,  310. 

plungers  for,  26;  design  of,  294. 

design  of  lower  casting  for  plungers 
on,  295,  297. 

design  of  valves  for,  269. 

how  to  remove  and  set  valves  on, 
270. 

weights  of  plungers  for,  267. 
Plungers,  construction  of,  for  lifts,  319. 

how  to  disconnect,  275. 

packing,  to  renew  the,  of,  267. 
Pressure,  arrangement  to  obtain  equal,  9. 

high,  systems,  14. 

low,  systems,  17. 

regulator,  30. 

tank  discharge,  232. 

tank  system,  30. 
Pump,  231. 

adjustment  between  pump  and  Stop- 
balls,  228. 

control  by  electrical  devices,  210. 
Pushing  and  pulling  horizontal  cylinder 
machine,  21. 

Rack  and  pinion  Valves,  263. 
Ropes,  care  of,  264. 

effect  of  stretching,  106. 

how  to  shorten,  107. 

in  the  "pulling"  type  of  horizontal 
elevators,  143. 

inspection  of,  need  of  continual,  106. 

in  Otis  running  rope  system,  85. 

replacing  of,  111. 

shackles  for,  109. 

standing  or  running  systems,  47. 

stretching  of,  90,  106. 

stretching  of,  in  Whittier  machine, 
167. 

unequal  stretching  of,  66. 

Safe-lifters,  315,  319. 
Safety,  plank  37. 

device,  60. 

Otis,  governor,  38,  60. 
Settling,  causes  of,  90,  269. 
Shackles  for  elevator  ropes,  109. 


Sheave  frames,  travelling,  112. 

supports  for,  how  to  strengthen,  116. 
Sheaves,  carrier  rollers  for  rope  sheaves, 

179. 

construction  of,  in  high  pressure  ma- 
chines, 196. 

for  horizontal  machines,  171;  lubrica- 
tion of,  170. 

overhead,  171;  lubrication  of,  173. 
Otis  ball  and  socket  bearing  for,  172. 
in   "pulling"   type  horizontal  eleva- 
tors, 143. 

traveling,  construction  of,  138. 
Shoes,  guide,  64. 

replacing  worn,  on  Otis  plunger  ele- 
vators, 274. 

Simple  balanced  valve,  8. 
Speed,  controlling,  of  elevators  by  valve 

movement,  260. 
high  speed  valves,  263. 
regulating  by  pilot  valves,  129. 
regulators,  52,  58,  217. 
Standard    plunger    elevator,    279,  284, 

291,  292,  300,  315. 
Spring-cushion  chamber,  232. 
Stop,  automatic,  at  top  and  bottom,  20, 

35,  100. 
balls,  20,  100. 
motion  gearing  on  Whittier  machine, 

167. 

valves,  101,  155. 

valves,    automatic    with    accumula- 
tors, 228. 

Strainers,  the  importance  of,  174. 
Stuffing-box,  casting,  268. 

replacing,  how  to  determine  whether 
it  needs,  269. 

Two-to-one  geared  machines,  4. 
Three-to-one  geared  machines,  5. 

Upright  plunger  elevators,  6. 

Valves,  automatic  stop,  56. 
with  accumulators,  228. 
on  plunger  elevators,  240,  252. 
on  Otis  elevators,  271. 
comparison    between,    on   vertical   and 

horizontal  machines,  23. 
construction  and   operation   of,   261; 
on  Whittier  machines,  144. 


325 


INDEX 


Valves,  on  Morse  and  Williams  machines, 
149,  151,  153,  184. 

circulating  and  non-circulating,  83. 

differential,  98. 

freight  elevators,  on,  291. 

high-speed,  263. 

leak  in,  caused  by  settling,  91. 

magnet,  control  of,  66,  68. 

main,  operation  of,  135. 

modification    in,   controlled  by  mag- 
net, 202. 

on  Otis  machine,  244;  latest  design, 

249. 
Valves, 

operation  of  pilot,  135;  on   plunger 
elevators,  287 


Valves — Continued. 

packing  of  high  pressure,  225. 
pilot,  and  main,  control,  arrangements 
for,  254;  on  high  pressure  machines, 
198. 

piston,  on  plunger  elevators,  253. 
rack  and  pinion,  263. 
removal  and  setting  of,  270. 
relief  pipe  for  discharge,  on,  173. 
simple  balanced,  8. 
stop,  100. 

speed  regulating,  58. 
Water-balance  elevator,  3. 
Whittier  Machine  Co.'s  "pulling"  type 
elevator,   142,   147,   165,  215;  stop 
valve  mechanism,  166,  215. 


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